China said Thursday the details concerning a suspected Chinese fishing boat sunk by a Republic of Korea (ROK) cargo ship are still unknown.

"The situation concerning the boat's crew members is unknown," Chinese Foreign Ministry spokeswoman Jiang Yu said at a regular press conference.

All crew members of the fishing boat are unaccounted for.

The suspected Chinese fishing boat sunk in waters off the ROK coast at around 11:50 a.m. Wednesday.

The boat's name and the exact number of sailors aboard was not available.

The Chinese embassy in Seoul has urged the ROK to rescue the missing sailors, Jiang said.

The ROK Coast Guard sent a patrol vessel and a helicopter to the scene to search for the sailors but a typhoon has hindered the rescue work.