Four people were dead while four others remained missing after a mainland sand carrier capsized in the waters of the Penghu archipelago on Sunday evening, Taiwan's coast guard authority said Monday.

One of the nine crew members on board was rescued, according to a briefing by the maritime rescue center of the Guangdong Maritime Safety Administration on Tuesday.

Rescue forces across the straits joined hands in searching for the crew members.

Eighteen divers were dispatched by the Nanhai Rescue Bureau and the Guangzhou Salvage Bureau based in south China's Guangdong Province, and the Donghai Rescue Bureau based in Shanghai, of the Ministry of Transport. They have explored all possible cabins of the wrecked ship to rescue one survivor and retrieve four bodies.

The rescue efforts are still underway.