All crew members went missing after a Chinese fishing boat was sunk by a South Korean cargo ship in waters off west coast of South Korea later Wednesday, the consulate office of the Chinese Embassy to South Korea told Xinhua.

Seoul's Coast Guard informed the embassy that the Chinese fishing boat, whose name and detailed conditions remain unknown, was sunk by the 1,250-ton cargo ship Ocean Ace No. 6, owned by South Korea's HC freight company, in waters about 68 sea miles ( about 126 km) west off west-Gyengnyelbi islet, South ChungCheong Province, at around 14:25 p.m. local time (0525 GMT) Wednesday, the consulate office said.

All crew members on board went missing immediately after the accident took place, and the exact number of the sailors is still not available, it added.

The Chinese embassy asked South Korean side to make full efforts to rescue the missing sailors, it said.

The rescue operation are underway as Seoul's Coast Guard has sent a patrol vessel and a helicopter to the scene for searching the missing people.