Both candidates in Brazil's presidential election called for their rival's disqualification Tuesday over allegations of social media malfeasance, according to court filings. Left-wing President Luiz Inacio Lula da Silva’s campaign said they will request the annulment of right-wing rival Flavio Bolsonaro's candidacy over alleged election interference by tech giant Meta, while Bolsonaro's team is accusing Lula of "abuse of power" in the mass sharing of government postings on WhatsApp.

Voters in oil-rich Alberta overwhelmingly backed remaining in Canada in the province's first-ever referendum on separation, with early results on Tuesday delivering a boost to Prime Minister Mark Carney’s push for national unity amid US President Donald Trump’s trade war and annexation threats.

Brazil’s top electoral court has given Meta 24 hours to prove it is treating campaign content from incumbent President Luiz Inácio Lula da Silva and Senator Flavio Bolsonaro equally on its online platforms, threatening a daily fine for noncompliance. The ruling follows allegations from Lula's campaign that the social media giant is suppressing Lula’s campaign content ahead of Sunday’s closely contested presidential runoff.

Brazilian President Luiz Inacio Lula da Silva and right-wing senator Flavio Bolsonaro traded personal attacks in a heated presidential debate on Sunday, a week before a closely contested run-off. The rivals accused each other of lying and corruption while clashing over the economy, security and healthcare ahead of the October 25 vote.

Four Canadian service members were killed and 39 people hospitalised after a fire broke out during military training at a base in Alberta on Saturday, officials said. Premier Danielle Smith said Sunday that at least 19 patients were in critical condition, with some suffering severe burns requiring prolonged intensive treatment.

US Secretary of State Marco Rubio said Saturday that US President Donald Trump’s decision to waive sanctions and tariffs on Russia would last 60 days, as the move drew bipartisan criticism and raised fears in Ukraine that Washington could ease further restrictions on Moscow.

US President Donald Trump on Friday put a sweeping package of sanctions and tariffs targeting Russian energy revenues on hold, saying the waiver was in the country's national interest. The relationship between Washington and Kyiv has been fraying since Trump struck a deal with Moscow to ease sanctions in exchange for Russia flooding the global market with diesel to bring down fuel costs.

A White House Press official said Friday that Secretary ​Katie Zacharia was "let go" from her role after US President Donald Trump signaled she was on her way out, a week after he picked her for the post. Zacharia's credentials as an attorney had come under scrutiny and she admitted to not having passed the bar in an interview with Fox News on Thursday.

Following US President Donald Trump's October 9 announcement of an agreement signed with Russian President Vladimir Putin to import Russian diesel into the United States, a number of pro-Russian social media accounts began claiming that a Russian oil tanker was already carrying thousands of barrels of diesel to the United States. The ship was actually carrying fertiliser. 

A 16-year-old gunman killed three children and a teacher at Silver Rail Elementary School in Bend, Oregon, on Thursday before being killed by a community member who pursued him inside, police said. Two other people were wounded in the shooting.

Ousted Venezuelan president Nicolas Maduro and his wife Cilia Flores pleaded not guilty on Thursday to new torture charges brought against them by US authorities, calling them “false allegations". The couple has been held in a New York jail since their capture in early January and is facing a new indictment accusing them of conspiring to torture political opponents and US citizens.

US President Donald Trump said Thursday that he was cancelling plans to livestream the firing squad execution of a convicted military base shooter – a project that had sparked outrage in the United States. Nidal Hasan is scheduled to be executed on December 3 at Fort Hood in Texas, where he killed 13 people in 2009.

An association in Haiti is organising capoeira classes – an Afro-Brazilian martial art – in an attempt to reduce community violence and promote social reintegration. The Observers team spoke to its founder, Rodney Jean Marc, who said their doors are open to everyone, “even children in armed gangs”. The initiative takes place as the country's security situation has worsened in recent years.

SpaceX CEO Elon Musk on Wednesday called on Ukrainian President Volodymyr Zelensky to "go" after Kyiv raised doubts over US support for his country against the Russian invasion. A day earlier, Musk said any restrictions on Ukraine's use of the Starshield system would be due to decisions made by the US government after Zelensky called on Musk to restore Starlink, which Kyiv says has been slowed down.

Thousands of Colombians protested peacefully across the country on Wednesday against right-wing President Abelardo de la Espriella, in the opposition’s first major demonstrations since he took office in August. Former leftist president Gustavo Petro led a rally in Bogota joined by trade unionists, Indigenous groups, students and feminist activists.

Brazilian President Luiz Inacio Lula da Silva’s party plans to file a complaint against Meta with the Organisation of American States alleging election interference, his campaign said Wednesday. The party accuses Meta of restricting Lula’s online content ahead of the October 25 presidential runoff against far-right Senator Flavio Bolsonaro. Meta denies the allegations.

The FBI said on Wednesday it has arrested a Saudi national employed as an engineer at OpenAI on suspicions that he had bugged a conference room at the company's San Francisco office with a "sophisticated recording device".

US President Donald Trump asked his ambassador to Greece Kimberly Guilfoyle to resign on Tuesday after reports alleged she sought $100,000 from a Trump supporter to pay personal credit card debt and accepted luxury trips and hotel stays from wealthy Greek businessmen. Guilfoyle denied wrongdoing and vowed to defend her reputation.

Duane “Keffe D” Davis, the former Los Angeles gang leader who boasted in books and interviews of his involvement in the killing of rapper Tupac Shakur, only to deny it when he came to trial, was sentenced to a minimum 40 years in prison on Tuesday.

"Breaking Bad" actor RJ Mitte, who played Walter White Jr. in the hit US television series, has died aged 34, his representatives said Monday. The actor, who lived with cerebal palsy, also became a prominent disability rights advocate, championing inclusion and representation in film and television.