MANILA, Philippines — Widespread flooding that killed at least 11 people, battered a million others and paralyzed the Philippine capital began to ease Wednesday as cleanup and rescue efforts focused on a large number of distressed residents, some still marooned on their roofs.

Government forecasters said the monsoon rains that overflowed major dams and rivers in Manila and surrounding provinces would gradually abate and lead to sunny weather Thursday after 12 days of relentless downpours.

The deluge was the worst since 2009, when hundreds died in rampaging flash floods.

“We’re still on a rescue mode,” said Benito Ramos, who heads the government’s main disaster-response agency. “Floods are receding in many areas, but people are still trapped on their roofs.”

Ramos said the massive flooding turned half of Manila into “a water world” on Monday evening and into Tuesday.