Four soldiers were killed and dozens injured in a fire at a military base in Alberta province, one of the worst peacetime tragedies to hit Canada's armed forces on home soil, Prime Minister Mark Carney said Sunday.

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.