Indian-origin Senator Kamala Harris launched her 2020 presidential bid on Sunday with a scathing rebuke of President Donald Trump's policies, alleging that the US democracy was under attack like never before.

Democratic presidential aspirant Tulsi Gabbard has alleged that she had become a victim of "religious bigotry" and some media outlets were targeting her and accusing her supporters, who have Hindu names, of being Hindu nationalists.

Prime Minister Justin Trudeau fired Canada's ambassador to China after the envoy said it would be "great" if the US dropped its extradition request for a Chinese tech executive arrested in Canada.

The death toll from the collapse of a dam holding back mine waste in southeastern Brazil rose to 40 on Saturday as searchers flying in helicopters and rescuers labouring in deep mud uncovered more bodies.

Two bombs minutes apart tore through a Roman Catholic cathedral on a southern Philippine island where Muslim militants are active, killing at least 27 people and wounding 77 others during a Sunday Mass, officials said.

Rescuers worked overnight into Saturday searching for around 300 people missing after a dam collapse at a mine in southeast Brazil killed at least nine, but the local governor said "odds are minimal" that they would be found alive.

President Donald Trump Friday announced a deal with opposition Democrats to temporarily reopen the US federal government, shut down for a record five weeks by a bitter row over funding for a US-Mexico border wall.

First Indian-origin Senator Kamala Harris, who recently announced her presidential bid for 2020, has sought an end to the unprecedented government shutdown and asked for earliest reopening of the federal government.