The entire region has been battered by torrential downpours for the last three days.
Some areas in Quang Tri Province and neighboring Thua Thien-Hue Province have received 980 mm of rain. Rainfall of 180 mm a day is considered heavy.
At least five people have been killed, two in Quang Tri and the others in Dak Lak, Gia Lai and Quang Ngai provinces. Seven others were missing as of Thursday night.
In Quang Binh, Quang Tri, Thua Thien-Hue, and Da Nang, 37 communes have been cut off as some areas are under one meter of water and traffic has been blocked due to landslides.
In popular tourist town Hue in Thua Thien-Hue, many roads are inundated.
Nguyen Van Khoa, a local official, said around 200 houses are under 30 cm of water and people living in low-lying areas have been forced to move to safety.
Hoi An, a tourist hotspot and UNESCO heritage site, is like a massive lake following prolonged downpours with many streets under 0.5 meter of water.
Nguyen The Hung, the town’s vice chairman, said plans are underway to evacuate people living in low-lying areas.
Prime Minister Nguyen Xuan Phuc on Thursday ordered provinces from Ha Tinh to Phu Yen to deal with the heavy flooding and take urgent measures including evacuation to ensure people’s safety.
The central region from Ha Tinh to Quang Ngai provinces should expect more heavy rains of 330-400 mm a day until Sunday, the national weather forecasting center has warned.