Seventy-four Chinese fishermen are missing after three fishing boats sank in the South China Sea after a typhoon hit the region.
The ships were hit by Typhoon Wutip last night as they navigated gales near the Paracel Islands, state news agency Xinhua said.
It is believed 14 survivors have been rescued. The boats were sailing from the southern province of Guangdong.
Rains from the storm reached Vietnam today and are due to hit Thailand tomorrow.
Thai officials warned that more heavy rains could inundate already flood-hit areas of the northeast.
At least 22 people have been killed in this year's flooding. Soldiers have been asked to help evacuate people trapped in flood zones.
Authorities in central Vietnam have moved children and elderly people to schools and other more solid buildings ahead of the storm.
In the central province of Quang Tri, an estimated 82,000 people would need to be evacuated if Typhoon Wutip made a direct hit, a government statement said.
Vietnam said heavy rain had been falling in several central provinces while flooding and landslides could strike the region later this week.