Six people were on the fishing vessel near the Taiwan-controlled islands, which lie just a few kilometres off China’s eastern coast.
Taiwan and China are conducting a joint rescue mission to find two missing crew members after a fishing vessel capsized near Taiwan’s Kinmen islands.
The boat carrying six people sank about 1.07 nautical miles (about 2km) southwest of the island chain’s Dongding islet at about 6am on Thursday (22:00 GMT on Wednesday), according to authorities in Taiwan.
Two people have been confirmed dead and two were rescued.
The area is sensitive because Kinmen is located just 5km (three miles) off China’s eastern coast.
The joint operation, which includes six Chinese rescue ships, comes a month to the day after the Taiwanese coastguard’s pursuit of a Chinese fishing boat in the area left two men dead, and added to the tensions between Taipei and Beijing.
Coastguard chief Chou Mei-wu told a parliamentary committee that Taiwan sent four boats after Chinese authorities sought help.
He said Chinese requests for assistance were common, with 119 people rescued in such efforts over the past three years or so.
“The waters are narrow around the Kinmen-Xiamen [area] and cooperation between Taiwan and China is very important,” he said, referring to the cities that face each other across the strait.
China’s coastguard began regular patrols around the Kinmen islands after last month’s incident. It also came under criticism in Taiwan after briefly boarding a Taiwanese cruise ship causing panic among the passengers.
Beijing claims Taiwan as its own territory and has not ruled out the use of force to achieve its goals.