Some villages were reduced to rubble by flash floods
Flooding and landslides in northwest Vietnam have killed at least 100 people and left 50 missing, officials say.
Tropical storm Kammuri battered mountain villages in Lao Cai province over the weekend, downing power lines and cutting transportation links.
Torrents of water swept entire villages away, local officials said, while other victims were buried under mountains of mud.
Hundreds of troops are using trucks and boats to reach people in flooded areas.
"We have reached some areas that had been isolated for two days," Thao A Tua, a local disaster relief official, told the French news agency AFP.
"We are focusing on finding the people still missing. It's bad, we are afraid they are dead and we'll have to recover their bodies."
The storm moved into the region on Friday, bringing high winds and heavy rain.
Lao Cai, which borders China, bore the brunt of it, but surrounding provinces were also hard-hit.
Roads and bridges have been washed away and more than 4,000 buildings flooded, the government said.
Sections of the rail link between Hanoi and Lao Cai were also blocked, stranding tourists on their way to the hill-top resort of Sapa, officials said.
More rain is expected in the region later in the day, potentially hampering the rescue effort.
Kammuri is the ninth tropical storm of the year.
Last week, China evacuated nearly 400,000 people and called thousands of vessels back to port as the storm lashed its southern coast.