People in Manila are still coping with floods in the aftermath of four storms this month. (Anthony Germain/CBC)

The fourth typhoon to whip the Philippines in a month was downgraded to a tropical storm on Saturday, but not before leaving flash floods and at least seven dead.

Strong winds and pounding rain lashed the capital, Manila, and nearby provinces before the storm headed back out to sea.

Police said six people, including a 12-year-old girl, drowned in a flash flood in Laguna province's Pagsanjan township, south of Manila. Four others were missing in flood waters in other towns, regional police Chief Perfecto Palad said.

A man drowned after being swept away by strong currents as he tried to cross a creek in Rizal province's Pililla township while carrying his one-year-old child, who remains missing.

A man and his son who were in a car on a bridge that collapsed in nearby Batangas province were also missing, said regional disaster officer Fred Bragas.

People stranded on roofs

One river in Laguna overflowed, flooding most of lakeside Santa Cruz town and sending residents clambering onto roofs, said Mayor Ariel Magcalas.

"We cannot move, this is no joke," Magcalas said. "The water is high. We need help," he said in a public address via Radio DZBB.

Authorities evacuated more than 115,000 people in nine provinces east and south of Manila in the path of Typhoon Mirinae.

The muddy flood water receded as rains eased, but was still chest-high in some communities.

In Manila, residents hunkered down in their homes overnight as rains beat down on dark, deserted streets. Mirinae passed south of the sprawling city of 12 million.

Mirinae tracked the same route as tropical storm Ketsana, which in late September dumped the heaviest rains in 40 years in and around Manila. A week later, Typhoon Parma triggered massive landslides in Luzon's mountain region.

Nearly 95,000 people who fled during those two earlier storms were still housed in temporary shelters when Mirinae struck, the national disaster agency said.

Flights at Manila's international airport were cancelled and about 8,000 ferry passengers were stranded as the coast guard grounded all vessels.

Manila electric power distributor Meralco said the high winds had forced outages in many areas around the capital, but electricity was restored in most areas by Saturday afternoon.

Back-to-back storms in late September and early October killed more than 900 people, and a third storm then threatened the northern Philippines before veering toward Japan.