Buffeted by strong winds, a vessel loaded with 3,000 tons of sand sank in the Bohai Sea off Huanghua Port, Cangzhou City, Hebei Province. Seven bodies have already been recovered.

The owner of the ship, from the coastal city of Penglai, Shandong Province, told Hebei maritime authorities on Sunday that ten sailors were onboard the boat, prompting rescuers to search the area for the missing three, the Huanghua Maritime Safety Administration said.

"We received a call asking for help from the vessel at about 5:15 am Saturday. Then we lost contact with it," said Zhang Zhaoxu, deputy director at the administration's command center.

The provincial maritime rescue center organized ships and helicopters to conduct search and rescue operations, but the efforts were hindered by strong winds and large sea swells, he said.

"We will expand the rescue area and send divers to the cabin of the vessel to search for the missing," said Wang Baolin, director at the administration.