Landslides and floods killed at least 62 people in northern Vietnam, covering the homes of some victims as they slept in their beds, disaster officials said on Saturday.
Dozens more were reported missing and officials feared the death toll would rise as they struggled to reach isolated communities.
With heavy rain continuing on Saturday, rescue workers were trying to move people to higher ground.
The province of Lao Cai was the hardest hit, with 25 people reported dead and 35 missing, said provincial disaster official Thao A Tua. Tens of thousands were stranded by the floods, which began on Friday, Tua said.
"The death toll is likely to increase because heavy rain is still falling and the rivers in the area are rising," Tua said.
In neighboring Yen Bai province, floods and landslides killed 25 people and torrents carried some people kilometers from their homes, said disaster official Luong Tuan Anh. Four people were still missing, he said.
"The water and walls of mud came at night when everybody was sleeping," he said. "They could not run to safety."
Twelve people were found dead and another was missing in Quang Ninh and Phu Tho provinces, as rampaging waters knocked down trees and electricity pylons and washed away houses, officials said.
Vietnam is prone to floods and storms that kill hundreds of people each year.