Typhoon Molave has slammed into Vietnam with destructive force, causing at least two deaths and sinking two fishing boats with 26 crew.

It was feared to be the most powerful storm to hit the country in 20 years.

Winds of up to 93mph killed a man by knocking him off his roof as he was trying to reinforce it in south-central Quang Ngai province. Another man was killed by a falling tree in the coastal province, the official Vietnam News Agency reported.

The navy deployed two rescue boats to search for the 26 fishermen off Binh Dinh province, according to state-run VTV network. It was not immediately clear if anyone was saved in the stormy waters.

TV footage showed ferocious wind rattling roofs and toppling trees in Quang Ngai. In the nearby coastal province of Phu Yen, key roads were littered by fallen electricity posts, trees and billboards, and the wind ripped off roofs from many houses and ravaged fish farms.

At least 40,000 people have been evacuated to emergency shelters farther inland from coastal villages.

VTV showed displaced villagers huddled in classrooms that were converted into an evacuation centre, where they spent the night.

Provincial authorities shut down offices, factories and schools and asked people to remain indoors to prevent casualties. Vietnam is still recovering from severe flooding and landslides that killed 136 people and left dozens missing in three provinces.

At least five airports were closed as the typhoon approached, with more than 200 flights cancelled. Train services were also suspended and will resume when the weather improves, VTV reported.

The typhoon left at least nine people dead in the Philippines before blowing towards Vietnam. Most of the thousands who took shelter during the storm have returned home, leaving those whose homes were destroyed in evacuation camps.