Philippine authorities warned Monday an approaching storm could bring more heavy rain to the capital and surrounding areas that are still reeling from devastating floods that have left 92 dead, AFP reports.
Nearly half a million people are packed in evacuation centres, while all in all, more than 3.4 million people have been affected by the floods, the National Disaster Risk Reduction and Management Council said.
Flooding in Manila has largely subsided, although hundreds of thousands remained cut off by neck-deep floods in low-lying farming towns north of the capital that are natural catch basins.
"These are the people we are most worried about," civil defence head Benito Ramos told AFP.
"We have not yet fully recovered and here comes another storm."
"We will continue with our alert levels until we see the full effects of this approaching weather disturbance."
Monday morning the state weather bureau said a tropical depression was spotted 600 kilometres (370 miles) off the eastern coast of the Philippines in the Pacific Ocean.
It was forecast to move in a west-northwest direction and likely skirt the Philippines, but it could still bring heavy rains by Monday night, the bureau said.
The storm could interact with the seasonal southwest monsoon and lead to fresh torrential rains, it said.
Similar heavy rainfall submerged more than 80 percent of the capital Manila last week, virtually bringing the megacity to a standstill.
Authorities said they were checking for possible outbreaks of disease and rushing food packs to evacuation centres, while the death toll had meanwhile risen to 92 from 85 reported Sunday.
Many of the casualties were due to drowning.
In Malabon, a coastal district facing Manila Bay, people trickled back to clean up their mud-streaked homes Monday amid warnings to be prepared for fresh evacuations.
"Many have returned to their homes to rebuild, but sadly they may have to leave again if there are more floods because of this new storm," said Roderick Tongol, head of Malabon's disaster response unit.
"We are on heightened alert, and we have placed all our rescue teams on standby ahead of this new storm," he said.
Virtually all of Malabon's 21 villages were swamped by neck-deep floods at the height of the torrential rains, and some 1,000 people still remained in evacuation centres Monday.