Media playback is unsupported on your device Media caption Footage shows widespread flooding across Toronto

About 50,000 people are still without power a day after a heavy rainstorm in Toronto flooded parts of Canada's largest city.

More than 90mm (3.5in) of water - over a month's average - was dumped on the city late on Monday, officials say.

The rain flooded some major roads and subway stations, causing traffic chaos.

Hundreds of passengers were stranded for several hours on a flooded commuter train and had to be evacuated on police boats.

Water levels on the rush-hour Richmond Hill train rose so high that passengers fled to the upper decks of the coaches.

'Unprecedented'

The commuters had to be rescued by police and firefighters in small inflatable boats.

Emergency officials said five or six people were treated at the scene for minor injuries.

There's a full-on river on either side of us... We. Are. Stuck. Hard Jonah Cait, stranded train passenger

At the height of the outages, about 300,000 people were without power, utility company Toronto Hydro said.

The power company brought outages down to 20,000 early on Tuesday, but an additional 30,000 lost power over the course of the morning.

Utility officials asked residents to limit their use of electricity as the system was under extreme strain.

Many basements and swimming pools in the area have been flooded with sewage and some roads remain underwater.

Porter Airlines cancelled all flights out of the downtown airport on Monday because of the extreme weather.

While the city saw about 90mm of rain, 126mm fell at nearby Pearson International airport on Monday evening, breaking the daily record of 121mm set by Hurricane Hazel in 1954.

Average rainfall for the entire month of July in the area is 71 mm.

Transit rail services were suspended in one area where a station and tracks were still underwater.

Toronto Mayor Rob Ford told reporters in a press conference on Tuesday he was generally satisfied with response efforts from emergency and city officials, but would order a full review to see what more could have been done.

"Toronto has persevered," Mr Ford was quoted by the CBC as saying, calling the rain "unprecedented".

"This is crucial that we all reduce our electricity for today to help relieve the strain on our hydro system. We're hanging on by a thread right now."

The area is under threat of another thunderstorm this evening, according to Environment Canada.