Tropical Storm Meari caused chaos across the Philippines on Thursday, dumping heavy rains in the capital, leaving 11 people missing in other parts of the country and grounding dozens of flights.

Head-high floods swept through parts of Manila during the evening rush hour, leaving thousands of people stranded in their cars and others in their offices as traffic turned to gridlock.

Authorities said they had dispatched rescue workers in rubber boats to help residents of badly-affected riverside areas.

There were no immediate reports of casualties in Manila, but authorities said at least 11 people were missing and thousands of others had been forced to flee their flooded homes elsewhere in the Philippines.

More than 7,000 people were evacuated from their homes in the Bicol peninsula of the main island of Luzon, said Raffy Alejandro, civil defence officer for the mainly rural region.

Ten fishermen were declared missing after they failed to return to port in Bicol, Alejandro said, adding that heavy seas prevented authorities from launching a search operation.

A woman had also been washed away by a flash flood in Bicol and authorities did not know whether she was alive, Joey Salceda, governor of one of the provinces in the region, said in a television interview.

Aviation authorities cancelled at least 56 flights to and from Manila, the National Disaster Risk Reduction and Management Council said. Thirty were foreign flights.

The state weather service said Meari had not directly hit Luzon, but it had caused a lot of damage across the island because it combined with seasonal monsoon weather and a tropical depression at sea.

It had packed maximum gusts of 90 kilometres (56 miles) an hour on Thursday, said government weather forecaster Sonny Pajarillo, adding that the storm could continue dumping rains on Luzon until Sunday.

An average of 20 storms and typhoons, some of them deadly, hit the Philippines every year.

Over the past six weeks, more than 50 people have been killed in a series of storms, one of which became a typhoon.