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Manila, Philippines (CNN) -- Thursday brought no break from the rain for nearly 2 million people in the Philippines, where a monsoon has caused heavy flooding, evacuations, and at least 19 deaths, disaster officials said.
Frequent rains over the main island of Luzon, where the capital is located, may trigger flash floods and landslides, the National Disaster Risk Reduction and Management Council said. Scattered showers and thunderstorms were forecast for the southern island of Mindanao and for the Visayas islands south of Luzon.
The number of people killed in the rains since Monday rose to 19 on Thursday, the disaster council said. Most were victims of a landslide in the Manila suburb of Quezon City; others died of drowning or electrocution. Three others are missing, the council said.
More than 3,000 homes have been damaged in the rains, it said.
While it is the summer monsoon season in the Philippines, the rain and flooding were exacerbated by recent Tropical Storm Haikui, the Philippines weather service said. Haikui made landfall on the east coast of China early Wednesday.
The latest downpours came on top of days of rain that had already drenched the area, with August generally the wettest month of the year. Heavy wind and rain in the past few weeks already left 53 people dead.
As of 6 a.m. Thursday, more than 450,000 families -- or nearly 2 million people -- were affected by the rains and floods, the disaster council said.
It recorded "severe" flooding in 89 municipalities.
Some of the Manila region's 12 million residents returned to work Wednesday, with some stores reopening and heavy congestion on the sodden roads, but the real clean-up is expected to start Thursday.
Hundreds of thousands of people are now in emergency shelters, and it may be a while before they can safely leave, CNN forecaster Mari Ramos said.
An additional concern is that the water will take days, or perhaps weeks, to recede in the lower-lying areas, she said. There could also be further flooding "downstream" as the water drains through the flood plain in the southern portions of metro Manila near Laguna de Bay.
This is an area that frequently suffers from serious flooding and was one of the hardest hit during the historic flooding that came with Tropical Storm Ketsana (local name Ondoy) in 2009, Ramos said.
In an effort to save lives and make way for rescue and relief efforts, government offices and schools were closed Tuesday and Wednesday, the office of President Benigno Aquino said. Some schools will remain closed Thursday, PNA reported.
The Philippines had already been lashed by heavy rain and wind in recent weeks resulting from Tropical Storm Saola, which plowed past it before hitting Taiwan and China at the end of last week.
In December, Tropical Storm Washi left more than 1,200 people dead after it set off flash floods that swept away entire villages in the southern Philippines.