More than 200,000 flood-battered residents of the Philippine capital fled their homes on Tuesday as relentless monsoon rains, which have killed eight people, submerged more than half of Manila.

More than 200,000 flood-battered residents of the Philippine capital fled their homes on Tuesday as relentless monsoon rains, which have killed eight people, submerged more than half of Manila.

Streets turned into rivers with water rising above two-metres (seven feet) in some parts of the megacity of 12 million people, while vast areas of neighboring farming regions on the main island of Luzon were also inundated.

"I was crying when I saw my house being filled with water," said Edita Selda, 68, a sidewalk vendor who was forced to evacuate from her home in a shantytown along a major river in Manila that burst its banks.

"I chained the door shut so our belongings wouldn't be washed away. But the water is moving so fast."

More than half of Manila was flooded on Tuesday morning although that figure subsided to about 20 percent by the evening, authorities said.

In one part of the capital, 47.5 centimetres (18.7 inches) of rain fell in the 24 hours to Monday morning, according to Esperanza Cayanan, a meteorologist in charge of Manila for the state weather forecaster.

She said this was the same amount which normally fell for all of August, already one of the wettest months of the year.

More than 200,000 people have sought shelter in evacuation centres, the head of the Philippine Red Cross, Gwendolyn Peng, told ABS-CBN television.

Countless others were forced to wait out the floods in their water-filled homes, while the less fortunate sat on sidewalks with only plastic sheets for protection from the rain.

"We have had nothing to eat, nothing to wear. A few people went to houses on higher ground, but most of us had nowhere to go," Dinah Claire Velasco, 44, a resident of a blue-collar coastal district on the outskirts of Manila said.

"My children and other people were able to seek refuge on the second floor of my house but a lot of others had to just sit on their roofs... We're waiting for rescue, for help, even just food."

While no-one was reported killed in Manila, five more people were confirmed to have drowned in flooded farming provinces to the north, according to the government's disaster management council.

Among them were a one-year-old baby and a 64-year-old man, both of whom drowned in the rural province of Pampanga about an hour's drive north of Manila.

This brought the confirmed death toll from two days of flooding across Luzon to eight.

The economic toll has also started to grow, with the stock exchange, government offices and schools in Manila closed for a second consecutive day.

More than 160 domestic and international flights at Manila's airport were cancelled.

The state weather agency said the rain would continue into Wednesday, raising the prospect of another day of paralysis in Manila.

The heavy rains were due to the seasonal monsoon being exacerbated by Tropical Storm Trami, known locally as Maring, which was hovering to the north of the Philippines.

Trami has been nearly stationary since Monday, according to the weather bureau.

The Southeast Asian archipelago endures about 20 major storms or typhoons annually, generally in the second half of the year and many of them are deadly.

The extent of the flooding across Manila recalled memories of Tropical Storm Ketsana, which flooded 80 percent of the capital in 2009 and claimed more than 460 lives.

However Ketsana took most people in Manila by surprise and its rain fell mostly in an eight-hour deluge. Residents and the government have also since taken many measures to be better prepared.

These include extensive social media alerts informing people about places to avoid and offering a platform to appeal for help.