Vu Van Luat said today that a couple and three of their children were killed yesterday when their home where they were sleeping was washed away by flash floods in the northern province of Lai Chau.
The couple's other child and their nephew suffered minor injuries in the incident, he added.
Flash floods also killed a baby girl and seriously injured her parents when their house was buried by a landslide in a nearby village, Luat said.
Vietnam is prone to floods and storms which kill hundreds of people each year.