More than 100,000 people have been evacuated from the path of Typhoon Ketsana as it bears down on central Vietnam, an official said on Tuesday.
As a weaker tropical storm, Ketsana battered the Philippines at the weekend, killing at least 240 people and rendering nearly 400,000 homeless.
Ketsana has since intensified in strength as it crosses the Pacific and, according to Vietnamese government forecasters, is likely to slam into the coast of central Vietnam later on Tuesday.
The Hong Kong Observatory said that as of 0200 GMT, Typhoon Ketsana was centred about 130 kilometres (80 miles) east-southeast of Danang and was moving west towards central Vietnam at about 12 kilometres per hour.
Authorities have mobilised several thousand military personnel and police to help residents out of the typhoon path, according to Nguyen The Hung of the national flood and storm control committee.
"Most fishing vessels have returned to port," he said. Vietnam Airlines on Monday said it was suspending flights to the central tourism hubs of Danang and Hue.
Hung said "serious flooding" was feared and that residents who have not evacuated should stay indoors and avoid all non-essential travel.
Tropical storm weather in the past week has already killed 18 people in central Vietnam, including from drowning, electrocution and accidents, the official said.