Scores of residents in the Klang Valley were evacuated and others were trapped in their homes on Sunday after heavy overnight rain triggered flash floods, a disaster response official said.

Four hours of continuous rain caused the Damansara river west of Kuala Lumpur to burst its banks and flood hundreds of homes in Shah Alam and surrounding areas.

"Up to 400 homes have been flooded and we have so far evacuated 150 people," said Borhan Madon, an officer with the fire and rescue department.

Borhan said floodwater in Kebun Bunga village was up to two metres deep.

"We are still evacuating people in our boats. But many refuse to move out," he said, adding that some 84 personnel are involved in the rescue.

Two highways closed

Two people were rescued from treetops and scores of cars were trapped as fast-rising water early Sunday caught many by surprise.

Two major highways into and out of the capital had to be closed to traffic. Rail service in the affected areas has also been disrupted.

"In some areas, only the roofs of cars caught in the floods could be seen. Murky water also flooded private homes," an AFP photographer at the scene said.

Borhan said more rain was expected and urged residents to remain on alert.