Flood-battered residents of the Philippine capital and surrounding areas appealed for help Tuesday as relentless monsoon rains, which have claimed at least seven lives, submerged more than half of Manila,
Water engulfed entire homes and vehicles in large parts of the megacity of 12 million people, trapping many people and forcing tens of thousands into evacuation centres.
"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 told AFP.
"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."
But groups involved in the rescue effort said they were being overwhelmed.
"We are getting a lot of calls for rescue... we would really be hard pressed to rescue all of them," a Philippine Red Cross official told a government briefing on the floods, which was broadcast on national television.
At least 60 percent of Manila was flooded on Tuesday morning, with some places enduring waters climbing as high as 2.1 metres (seven feet), an official with the Metropolitan Manila Development Authority told the briefing.
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 as which normally fell for all of August, already one of the wettest months of the year.
While no-one had been reported killed in Manila, four more people were confirmed to have drowned in flooded farming provinces to the north, said Reynaldo Balido, a spokesman for the government's disaster management council.
This brought the confirmed death toll from two days of flooding across the main island of Luzon to seven.
The economic toll also started to grow, with the stock exchange, government offices and schools in Manila closed for a second consecutive day.
Many domestic flights at Manila's airport were cancelled, while international flights were delayed on Tuesday morning. Flooded roads to the airport were impassable.
The state weather agency warned the rain would continue through Tuesday, issuing its top level red alert for Manila and neighbouring provinces.
The red alert means "serious flooding" is likely in low-lying areas, and more than three centimetres (1.8 inches) of rain is expected every hour.
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 had 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 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 residents as well as the government have 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.
One of the most important tools this week has been the #RescuePH hashtag on microblogging site Twitter.
"URGENT RESCUE: floods now reaching the second floor of houses there. #RescuePH" one post said, identifying the location of the district in Manila.