Four people in Canada, including two children, have been reported missing in flooding caused by torrential rains in Nova Scotia, police have said.

Officials say the heaviest rains to hit the Atlantic region in 50 years have triggered floods that have left thousands of homes without electricity.

Three months of rain fell in just 24 hours in some areas.

Residents have been urged not to join in searches for the missing due to the dangerous conditions.

The two missing children were in a car that was submerged by flood waters, police reported. The three other people in the car managed to escape.

A man and a young person are also missing after the vehicle they were in was also submerged. Two people were rescued from the vehicle.

Roads have been washed away and bridges have been weakened in Nova Scotia, where a state of emergency has been announced in some areas.

“We have a scary, significant situation,” said Nova Scotia Premier Tim Houston, adding that at least seven bridges would have to be replaced or rebuilt.

“The property damage to homes … is pretty unimaginable,” he told a news conference.

He estimated that is could take several days for the waters to recede.

More than 80,000 people were left without power at one point.

Prime Minister Justin Trudeau said he was very concerned about the floods and promised that the government “will be there” for the province.

Environment Canada says torrential rain in the eastern area of the province could continue into Sunday.

“People should not assume that everything is over. This is a very dynamic situation,” Halifax Mayor Mike Savage told a press conference.

He added that the city had been hit by “biblical proportions of rain”.

The flooding is the latest extreme weather event to hit northeast Canada – recent wildfires have burnt a record area, sending clouds of smoke south into the US.

There has also been extreme flooding in the US this month. The body of a two-year-old girl found along a river in Pennsylvania is believed to be one of two missing children swept away by flash floods last weekend. Her nine-month-old brother is still missing.

Scientists cannot say for certain that such extreme rainfall is caused by climate change, but the floods are consistent with the changes they expect in a warming world. This is because the warmer the earth becomes the more moisture the atmosphere can hold. This results in more droplets and heavier rainfall, sometimes in a shorter space of time and over a smaller area.