The victims came from five different provinces, 10 of them from mountainous Son La, said an online report from the national flood and storm control department. State media had reported 16 dead on Friday.
Another three bodies have been recovered in Lang Son province which borders China, bringing the death toll there to seven, said Bui Thanh, a provincial disaster official.
“These people were swept away during floods,” he told AFP, adding that little rain had been reported since Saturday morning.
In Bac Giang province, two boys aged four and 10 and a mobile phone company technician were among the latest victims of the floods.
“The man, from Viettel company, fell into the strong currents while he was trying to prevent flood water from entering a telecom station,” said Bui Lien Son, deputy head of the province’s flood and storm office.
A total of 27 people have been reported injured. Thousands of houses were inundated or destroyed while more than 97,700 hectares (241,000 acres) of crops had been damaged since floods and heavy rains ravaged the region on Wednesday night.
State-run television VTV showed people in Bac Giang and Quang Ninh provinces taking refuge on the roofs of houses flooded to the eaves or on hills.
“This is the second time we were hit by floods in this province this year,” La Van Nam, a local resident in Bac Giang province told VTV. “We are in real difficulties as the floods damaged our rice crop,” he added.
According to Vietnam News Agency, several remote communes in Quang Ninh and Son La provinces were cut off. Disaster officials have warned of possible landslides in the mountainous regions, it said.
Nearly 5,300 soldiers have been mobilised for search and rescue operations and to help people recover in the aftermath of the floods, said the online report from Hanoi.
Vietnam suffers from frequent floods and storms, which claim hundreds of lives every year between July and November.