Flash floods from a powerful typhoon that swept through the Philippines and China earlier in the week have killed at least 21 people in Vietnam, the government said on Saturday.
Thousands of homes were either washed away or destroyed in northern Vietnam as typhoon Hagupit brought heavy rains and landslides, the government's storm and flood prevention committee said in a report.
Hagupit, which means "lashing" in Filipino, killed at least eight people in the Philippines and three in China where it triggered a "once-in-a-century storm tide".
The Vietnamese army sent 3,400 soldiers to rescue and evacuate thousands of people out of areas vulnerable to more flash floods and landslides in the mountainous provinces of Son La, Lang Son and Bac Giang.
Four people were not yet accounted for since floods hits the northern areas and 30 were injured, the government said.
The water level in two swollen rivers, Ky Cung and Thai Binh is expected to rise swiftly on Saturday and peak at 5.5 metre on Sunday, the National Metereology Centre's forecast said.
Vietnam's main agriculture belt, including the coffee-growing Central Highlands region and the Mekong Delta rice basket, was not on the storm's path.