Streets in the capital Hanoi remained submerged with up to 1 metre (yard) of water after torrential rains, described as the heaviest since 1984.
"It is a total nightmare here, no one would ever think this kind of flood can happen in the capital," said Nguyen Minh Hai, who spent Friday night stuck in his car.
Rescue workers were searching for a doctor for the National Sports Athlete Clinic in Hanoi who was believed to have been washed away in a canal on Friday, the Vietnam News Agency reported.
Torrential rain continued to pound northern Vietnam on Saturday, the weather office said, threatening dangerous flash floods in six mountainous provinces.
"Flash floods on the Hoang Long river in the north and rivers from Thanh Hoa to Nghe An will continue to rise," the government's storm and flood control committee said in a flood report on Saturday.
The report said at least nine people were killed on Friday alone in several northern and central provinces including two children in the capital Hanoi, taking the total toll in the past week to more than 20.
Many residents in Hanoi abandoned their cars and motorcycles.
More than 400 mm 330 mm (16 inches) of rain had pounded Hanoi since Friday, halting traffic, while landslides had eroded many sections of the north-south Ho Chi Minh highway in Thua Thien-Hue province.
Vietnam's main agricultural area, including the Central Highlands coffee belt and the Mekong Delta rice basket, has not been affected by the floods, although rain disrupted coffee harvesting this week.
The harvest is due to peak in mid-November in the Central Highlands, two weeks earlier than usual, but rain could prolong the drying process and damage bean quality, traders have said.
Typhoons and floods have killed several hundred people in northern and central provinces since the start of this year. The flood and storm season ends next month in the central region, which is widely exposed to the sea.
(Reporting by Nguyen Nhat Lam; Editing by Sanjeev Miglani)
- Reuters - Thomson Reuters Foundation
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