Heavy rain of up to 30 centimetres (12 inches) triggered the floods in the provinces of Son La, Phu Tho, Tuyen Quang and especially Dien Bien, isolating several communities.

The ministry of agriculture said three people were killed while a search is ongoing for nine others in Dien Bien province's Tia Dinh and Xa Dung communes.

State media quoted local authorities as saying rain was heavy from 3:00 am, triggering flash floods from upstream.

Several villages became flooded and remained inaccessible by Friday afternoon.

Last weekend, flash floods claimed five lives in Son La province, inundating crops and washing away poultry and cattle.

Vietnam is now in its tropical storm season, which often cause deadly floods and landslides.

Scientists say human-driven climate change is causing more intense weather patterns that can make destructive floods more likely.

In September 2024, Typhoon Yagi devastated northern Vietnam, leaving 345 people dead and causing an estimated economic loss of $3.3 billion.