Deadly torrential rains submerged much of the Philippine capital and surrounding areas today, forcing nearly 270,000 people to flee their homes with more flooding expected in the north of the country as a tropical storm passes through the region, officials said.

Steady rains for the past 10 days, killing more than 50 people, are set to continue until Wednesday, the Philippines weather bureau said, fuelled by tropical storm "Haikui" in the Philippine Sea northeast of Taiwan. The storm is headed for China's Zhejiang province where more than 250,000 people have been evacuated ahead of expected landfall late on Wednesday.

"It's like Waterworld," said Benito Ramos, head of the Philippines national disaster agency, referring to a Hollywood movie about a flooded world.

Schools , financial markets, and public and private offices were ordered shut, including outsourcing firms whose corporate clients are mainly from the United States and Europe.

Disaster officials said over half of Manila was swamped by floods as high as three metres, worsened by a high tide and the release of water from dams in surrounding provinces.

President Benigno Aquino, in an emergency meeting briefly interrupted by a power failure at the main army base in Manila, ordered officials to exert maximum effort to aid residents in flooded areas. Officials have deployed army troops, police and emergency workers with rubber boats and amphibious trucks.

The monsoon rains, which dumped about 300mm or three times the daily average of 80-100 mm from late yesterday to today, were the heaviest in three years, the weather bureau said.

Typhoon Ketsana, which swamped 80 per cent of the capital in 2009, aided a monsoon downpour of more than 450mm in a 24-hour period.