Asia's strongest storm this year, Typhoon Yagi, caused damages estimated at 81.5 trillion dong ($3.31 billion) across northern Vietnam, or twice as much as previous estimates, state media said on Saturday.

Manufacturers say that while many factories acted early to minimize damage, roughly 10 percent of buildings in Haiphong are deeply damaged.

Vietnam is preparing for more flooding with a tropical depression forecast to strengthen into a storm as it heads to its central coast, days after typhoon Yagi set off floods and landslides that killed more than 290 people in the north.

UNICEF is helping families meet urgent needs following flooding and landslides caused by Super Typhoon Yagi, the worst storm to hit Vietnam in 30 years.

Typhoon Yagi, the most powerful to hit Vietnam in over three decades, caused economic damage estimated at VND81.5 trillion ($3.31 billion) across northern Vietnam.

Asia's strongest storm this year, Typhoon Yagi, caused damages estimated at 81.5 trillion dong ($3.31 billion) across northern Vietnam, or twice as much as previous estimates, state media said on Saturday.

Even before the typhoon, the UN estimated 18.6 million people out of a total population of 55 million needed humanitarian assistance.