Fighters of the Bratstvo Battalion, part of the Timur Special Unit of Ukraine’s military intelligence agency (HUR), captured three Russian servicemen and gave first aid to one of them, HUR reported on 19 October. They also found and destroyed Russian sabotage groups, HUR said, adding that counter-sabotage operations in the Zaporizhzhia direction are ongoing.

Russian forces have spent months trying to get closer to Zaporizhzhia, one of Ukraine’s largest cities. They may try to use the dried-up bed of the Kakhovka Reservoir to infiltrate north toward it as autumn fog and dense vegetation set in, the Institute for the Study of War reported on 26 September. Ukrainian troops are now clearing the area of Russian saboteurs trying to get into the rear of Ukrainian positions, according to HUR.

HUR’s video shows the fighting and the captures, with one dead Russian soldier blurred. At the end, a captured Russian says two of the three men in his group were killed by a “Baba Yaga,” the nickname Russian troops use for Ukraine’s heavy bomber drones.

HUR described what the Russian groups are trying to do:

“Using small sabotage groups, the enemy is attempting to penetrate deep into the rear positions of Ukraine’s Defense Forces, build up forces to destabilize the situation, disrupt logistics, and neutralize Ukrainian defenders’ combat crews.”

Russia seeks to bring the front closer to Zaporizhzhia

Russia’s objective in the Zaporizhzhia direction is to advance within artillery range of the city, hold forward positions, and protect its rear from Ukrainian strikes, the Institute for the Study of War noted.

In January, Russian forces were trying to capture Stepnohirsk and advance along the shore of the former Kakhovka Reservoir toward Zaporizhzhia. Taking the settlement would let Russian troops place long-range artillery or fiber-optic drones there to strike the city’s outskirts, Southern Defense Forces spokesperson Vladyslav Voloshyn told Ukrinform on 14 January.

On 22 September, Anastasiia Shevchenko, spokesperson for the Southern Forces Group, said there were no signs of preparations for a direct offensive on Zaporizhzhia and that Russian forces lacked the troops and means to advance directly toward the city.

Dense vegetation and limited visibility: combat on the reservoir bed

The Kakhovka Reservoir was a vast artificial body of water on the Dnipro River in southern Ukraine that supplied water to millions of people, as well as to agriculture and industry. On 6 June 2023, Russian forces blew up the Kakhovka Hydroelectric Power Plant, the Southern Operational Command reported.

After the dam was destroyed, the bed of the former reservoir quickly became overgrown with willows, poplars, and shrubs, creating a new battlefield. Ukrainian troops have fought there before.

In November 2025, fighters from the same Bratstvo unit carried out a reconnaissance and sabotage operation 7 kilometers from the shoreline of the former reservoir, HUR said. They found and eliminated Russian troops, then raised the Ukrainian flag over the islands there and took control of the area.

In April, the Bratstvo unit’s chief of staff, who goes by the call sign “Dyviziia,” described the conditions on an earlier raid across the reservoir bed:

“You’re just constantly moving through these thickets, with no way to figure out which direction to go. You can literally see everything just two meters ahead of you.”

Ukrainian forces have liberated more territory since the beginning of the fall than Russian troops have captured during the same period. This trend has persisted throughout 2026, Ukrainian President Volodymyr Zelenskyy said in his 18 October address. He also reported that Dobropillia, Kostiantynivka, and five other settlements remain under Ukrainian control.

Russia systematically exaggerates its battlefield gains. A recent briefing by Valery Gerasimov, chief of the General Staff of the Russian Armed Forces, in which he claimed that Russian forces had captured 92 settlements since the beginning of September, as well as Kostiantynivka and Dobropillia, and advanced to within 5 kilometers of Zaporizhzhia, was based on “outright lies, manipulation, and exaggerations,” Ukrainian General Staff spokesperson Andrii Kovaliov said.

Ukraine also continues to defend areas near Kramatorsk, Zelenskyy said. He dismissed Russian claims about Zaporizhzhia.

“We are destroying Russians 20 kilometers from Zaporizhzhia, not five, as someone in Russia is fantasizing to Putin,” Zelenskyy said.

Ukrainian forces continue to hold back Russian assaults and destroy groups of occupying troops attempting to infiltrate Dobropillia, the president said. The Defense Forces are also defending positions elsewhere in Donetsk Oblast and in Kharkiv and Zaporizhzhia oblasts.

Zaporizhzhia axis: Russians seek to move artillery closer to the city

Russia seeks to advance on the Zaporizhzhia axis to bring the regional capital within range of its tube artillery, hold forward positions, and protect rear areas from Ukrainian strikes, the Institute for the Study of War (ISW) said on 18 October.

Maksym Kravchuk, spokesperson for Ukraine's Southern Group of Forces, refuted Gerasimov’s claims that Russian forces had captured Malokaterynivka, located south of Zaporizhzhia, stressing that the settlement remains under Ukrainian control, the Center for Countering Disinformation said on 18 October. Ukrainian troops recorded a video directly from Malokaterynivka to confirm this.

As of 18 October, Russian forces had advanced or infiltrated to within 24 kilometers of Zaporizhzhia, ISW said.

Dobropillia remains under Ukrainian control despite Russian assaults

Dobropillia is now a fortress anchoring Ukrainian positions along the highway leading northeast toward Kramatorsk. Russia first tried to take Dobropillia in August 2025 and is now trying again.

Russia is redeploying reinforcements to the Dobropillia axis and continues to send assault infantry through the village of Nove Shakhove despite heavy losses. Russian command will likely try to encircle or at least envelop Dobropillia and cut off Ukrainian supply routes from the direction of Bilozerske, Ukrainian military analyst Kostiantyn Mashovets wrote on 9 October.

Mashovets sees the push as the southern flank of a Russian effort to envelop the whole Sloviansk–Kramatorsk urban area.

Dobropillia remains under Ukrainian control, Zelenskyy said. On 18 October, footage located by analysts showed a Russian soldier hoisting a flag in the town's southeast after an infiltration, yet ISW has found no sign that Russian troops have dug in there.

Russia claimed to have captured Kostiantynivka, but ISW found no evidence

Ukrainian troops in and around Kostiantynivka are stopping Russia from locking in its gains in the city or pushing on toward Druzhkivka and Kramatorsk, ISW said on 17 October.

Russian officials claimed that capturing Kostiantynivka was an important step toward establishing control over the Sloviansk–Druzhkivka–Kramatorsk urban agglomeration and the entire Donetsk Oblast, ISW said in August. The Kremlin also claimed that Russian forces had captured the city as early as 5 July, the institute added.

A Russian military blogger claimed that Russian forces had full control over Kostiantynivka, but ISW found no evidence to support this claim, the institute said in its 16 October assessment. Russian troops had only infiltrated parts of southern and central Kostiantynivka without consolidating positions, and there was no evidence of their presence in its northern part, ISW added.

Ukraine has completed its Operation Vivaldi, aimed at protecting its fortress belt cities of Donetsk Oblast, which helped Kyiv preserve the region from Russian occupation for 12 years. Brigadier General Andrii Biletskyi, the commander of the Third Army Corps behind the operation, has reported that the fourth phase secured 101 km² of territory. Among the latest achievements is the liberation of three settlements—Zelena Dolyna, Lypove, and Kolodiazi.

The operation's main objective was to move Ukrainian troops into more advantageous defensive positions, Biletskyi said in the first days after the operation was made public. Vivaldi has now summed up the results of all four phases: Ukraine has established full control over 16 settlements, liberated 277 km² of territory, and inflicted 8,000 casualties on Russian forces.

Ukraine worked against Russia's deadline

During Operation Vivaldi, Ukrainian forces have prevented Russian troops from outflanking the Sloviansk-Kramatorsk agglomeration and cutting the Kharkiv–Sloviansk highway, a key supply route for Ukraine’s forces in Donbas, Biletskyi says.

“We thwarted the offensive of the Zapad grouping and forced it to redeploy some units of the 1st Tank Army, which eased pressure on Kupiansk-Vuzlovyi,” Biletskyi announces.

Previously, the Institute for the Study of War noted that Russian President Vladimir Putin was confident that Russian forces would be able to seize the entire Donetsk Oblast by the end of 2026 — the Kremlin’s latest deadline for achieving this goal.

Ukraine’s military was on a mission to prevent this.

Season one: clearing russian infiltration groups

On 15 September 2026, Ukraine’s Third Army Corps announced Operation Vivaldi in northern Donetsk Oblast. During the first phase, Ukrainian troops cleared Russian groups from 75 km² of territory and liberated another 10 km².

The Third Army Corps said it had struck Russian supply routes and fuel infrastructure, prompting Russia to relocate its fuel and lubricant reserves to Voronezh Oblast. According to the corps, Russian forces lost around 1,500 troops, more than 12,000 drones, and hundreds of pieces of equipment.

Season two: liberation of Shandryholove and Derylove

On 20 September, the Third Army Corps reported the liberation of Shandryholove and Derylove and the establishment of full control over Drobysheve.

During the second season, Russian forces lost another 800 troops, bringing their total losses across the first two seasons to more than 3,000, according to the corps.

During the first two seasons of the operation, Ukrainian troops and attached units regained control of 125 km² of territory, including 50 km² that had been fully liberated.

The first phase of Vivaldi involved eliminating Russian groups that had infiltrated Ukrainian positions, explained the commander of a battalion in the 125th Brigade, callsign Darwin, per ArmyInform. After clearing those groups, the Defense Forces moved on to the operation’s second phase, using reconnaissance drones to detect Russian forces, he added.

For this, Ukraine used UAVs and ground robotic systems.

“The Third Army Corps was the first in the world to begin deploying ground robotic systems by air. Our heavy bombers deliver kamikaze ground robotic systems more than 10 kilometers behind enemy lines,” Biletskyi noted.

Season three: advances near Novе and Ridkodub

On 28 September, the Third Army Corps reported the liberation of Nove, Ridkodub, and Katerynivka and the restoration of control over Karpivka and Novomykhailivka. Ukrainian forces regained another 51 km² of territory, bringing the total area liberated since the start of the offensive to 176 km². Russian forces lost around 2,000 troops, and more than 250 were taken prisoner, the corps said in its summary of the operation’s third phase.

“The Russians were convinced that the main axis of attack was Shandryholove–Zelena Dolyna. This led it to squander its reserves in counterattacks along that very axis. The Russians slept through the actual strike, which was focused on capturing Nove,” Biletskyi said.

Operation Vivaldi aimed to disrupt Russia’s plans in Donetsk Oblast

The need for Operation Vivaldi arose amid Russian attempts to encircle Ukraine’s fortified belt in Donetsk Oblast. Ukrainian forces conducted preparatory efforts aimed at degrading Russia’s offensive capabilities, including strikes on Russian drone operators, the Institute for the Study of War reported on 9 October.

Ukrainian counterattacks in the Lyman direction and east of Sloviansk and Kramatorsk were intended to complicate Russian efforts to seize the fortified belt in Donetsk Oblast, the report noted.

The corps advanced gradually, reclaiming small areas instead of attempting a large-scale breakthrough.

Ukrainian marines planned a clearing operation near Pokrovsk for about a month, their deputy commander said in remarks relayed by Army Inform. The Defense Ministry’s news agency published them on 12 October. He also described the Russian infantry the marines captured as barely trained, hungry, and unwilling to fight.

Russia seized Pokrovsk by seeping small infantry groups into the city a few at a time. Beyond the city, Russian advances stayed limited. ISW assessed on 25 February that the capture brought no further operationally significant gains. Small advances continued, and DeepState mapped one near Bilytske in Donetsk Oblast on 7 October. Every stretch where Ukrainian units stop that infiltration closes the route Russia used to take the city.

What the operation produced

Karyi, the 40th Separate Marine Brigade’s deputy commander, said that Operation Audit cleared about 6 km². The marines suffered no losses while inflicting them on the Russians, he said, and gathered a lot of intelligence. He promised the enemy many more surprises.

The brigade had announced an operation by the same name on 26 September. It said then that the marines had cleared 5 km² and captured two Russian soldiers. The brigade also said they had stopped the flow of Russian infiltration on that stretch of the Pokrovsk direction.

Two weeks of training, then the front

Karyi called the two prisoners typical of the Russian infantry now sent against the marines, with all of two weeks’ training behind them. He said Russian recruits spend a month on transfers and paperwork before going into battle. They then walk to their positions for one or two weeks.

If drones or Ukrainian ground groups don’t kill them first, he said, they surrender because they no longer want to fight. They are not fed or given water. He described one parcel a week with a can of stewed meat, and water drunk from the ground underfoot. That, Karyi said, is why the Russian troops facing the marines are demoralized and untrained.

Russia is concentrating missiles on a smaller, more specific set of targets, and its jet-powered attack drones are part of the reason, the Institute for the Study of War (ISW) assessed. Its combined attack overnight on 7 October killed 22 people in Pryluky, the State Emergency Service (SES) said as of the morning of 8 October. Russian milbloggers noted the shift the same day.

Russia often uses concentrated drone and missile strikes to overwhelm localized Ukrainian air defenses and destroy urban centers, ISW noted. Pryluky, where the strike killed children, was one of the areas a Russian channel says drew a significant share of the Kh-101s that night. With winter close, ISW expects the same pattern against Ukraine's energy grid, with jet drones partly letting Russia keep its missiles for priority targets without firing many more.

Missile waves on a few areas, Russian channels claim

Russia launched 48 Kh-101, Iskander-K, and Kalibr cruise missiles overnight on 7 October, Ukraine's Air Force reported. It also fired ballistic missiles, Zircon and Oniks anti-ship missiles, and 130 strike and decoy drones, 46 of them jet-powered Shahed-type models.

Russian milbloggers claimed the same day that Moscow had grouped a large part of its missile salvo into repeated waves on a few areas, while other weapons kept stretching Ukraine's air defenses elsewhere. The pro-war Russian Telegram channel Dva Mayora described the change as a switch from striking with splayed fingers to a series of hits with missile "fists." Defenders must then absorb a sharply rising load around one chosen site as one wave follows another, the channel claimed.

Citing Ukrainian monitoring channels, it claimed that roughly 30 or more Kh-101 cruise missiles flew toward Pryluky, Kremenchuk, Svitlovodsk, and Oleksandriia in Chernihiv, Poltava, and Kirovohrad oblasts. It put the Kremenchuk group at up to 15 missiles, Kh-101s and Kalibrs among them, aimed at the area of Kremenchuk and its hydroelectric plant.

Jet drones take some of the load off Russia's missiles

ISW said the jet-powered versions penetrate Ukrainian air defenses deeper and more reliably than propeller models. In ISW's assessment, that partly lets Russia concentrate cruise and ballistic missiles on priority targets without significantly raising missile use. Russia builds about 3,000 Geran-4 and Geran-5 jet drones a month, Ukraine's military intelligence agency (HUR) told Militarnyi in August.

ISW expects Russia to apply the pattern in a likely brutal winter campaign against energy infrastructure. Russia likely intends to make city life untenable and force Ukraine to capitulate to its demands, ISW assessed. Such tactics have not worked before and are unlikely to work now, analysts added.

They called cheap countermeasures to jet drones and small cruise missiles vital, alongside Western air defense aid such as US-made Patriots, which can stop ballistic missiles. Ukraine has already paired a Soviet-era Kub launcher with American RIM-7 interceptors to catch jet drones.