Reports from local authorities said that the accident occurred at about 6am when the 30-year-old woman and her two-year-old child were staying in a tent which was built to guard their fish pond.
"The flash flood coming from upstream suddenly ascended, sweeping the tent and the two people inside," said Ban Thanh Thao, chairwoman of Bat Xat District People's Committee. "We've sent a rescue team of 250 people to search for the two victims.
Many localities in the northern region have experienced heavy rains since Wednesday due to effects from a tropical depression.
It is forecasted that rains will continue on Thursday and the northern mountainous areas may see average rainfalls of 30-70 mm in the next six hours, causing possible flash floods and landslides.
