Typhoon Yagi weakened on Sunday after killing at least three people in Vietnam's capital Hanoi, flooding many neighbourhoods, downing thousands of trees and damaging houses, the government said.
Authorities warned of continued heavy rains, flash floods and landslides in northern Vietnam, where the storm, downgraded from a super typhoon, has killed at least seven and injured dozens since making landfall on Saturday afternoon, according to initial estimates.
Asia's most powerful storm this year claimed the lives of four people on the southern Chinese island of Hainan, according to the latest update from local authorities. The civil defence office in the Philippines, the first country Yagi hit after forming last week, raised the death toll there on Sunday to 20 from 16 and said 22 people remained missing.
Vietnam's meteorological agency said that by 4 a.m. on Sunday (2100 GMT on Saturday) Yagi had weakened to a tropical depression but warned of "risk of flash floods near small rivers and streams, and landslides on steep slopes in many places in the northern mountainous areas" and the coastal province of Thanh Hoa.
Calm returned on Sunday morning to Hanoi, a city of 8.5 million, after heavy winds and rains overnight caused widespread damage, leaving toppled trees scattered across the city centre and other neighbourhoods.
Hanoi's Noi Bai international airport, the busiest in northern Vietnam, reopened after closing on Saturday morning, state media said.
The government said Yagi had caused waves up to 4 metres (13 feet) high in coastal provinces, where rescue operations for those missing at sea were expected to start on Sunday when conditions allow. Coastal areas faced prolonged power cuts.
In Hainan, preliminary estimates suggested significant economic losses and widespread power outages, according to emergency response authorities cited by state-run Hainan Daily.