Torrential rains flooded several towns and cities in northern Texas on Monday, killing at least four people and destroying homes and buildings, officials said.

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Water floods the streets of downtown Gainesville on Monday. ((Tony Gutierrez/Associated Press))

Families and pet dogs were stranded on their roofs, waiting for rescue in Gainesville, near the Oklahoma border, one of the hardest hit towns. At least 500 homes in the town of 16,000 were flooded.

In Haltom City, a suburb of Fort Worth, at least 100 trailers were washed off their foundations.

"When I looked out the window, water was up to the bottom of the window and the current was so fast, houses were washing away," said Haltom City resident Rachel Hawkes.

"You could hear people screaming but we couldn't get out to help."

One four-year-old girl was swept out of her mother's arms in the city. She was found dead two hours later, the local fire department said.

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Joseph Rex, left, and Tyler Hall ride their bicycles past a stranded car in Gainesville on Monday. ((Donna McWilliam/Associated Press))

In Gainesville, a five-year-old girl and grandmother were killed when their family trailer was torn from its foundation and got wedged against a bridge in a swollen creek, said Cpl. Mike Linnell of the Texas Department of Public Safety. Rescuers pulled the girl's mother to safety and were searching for the girl's sister on Monday.

A woman died in Sherman, north of Dallas, when her stalled car was washed away by flood water.

Officials at the U.S. National Weather Service said Sunday night, the rain was coming down at a rate of 2.5 centimetres every 15 minutes.

"We get heavy rains in North Texas but the rate, the amount, the duration and the coverage of this are just amazing," said spokesman Gary Woodall.

Torrential rains also flooded creeks and rivers across central and southern Oklahoma.

Forecasters are calling for isolated thunderstorms in Texas and Oklahoma on Monday night and Tuesday.

With files from the Associated Press