BEIJING, April 18 -- Chinese diplomats have urged the Republic of Korea (ROK) to check the passenger list of its sunken ferry and make all-out search and rescue efforts, a Chinese Foreign Ministry spokeswoman said on Friday.

Spokeswoman Hua Chunying said at a daily press briefing that the Chinese Embassy in the ROK and the Consulate General in Kwangju have confirmed a fourth Chinese citizen aboard the ship based on information from the ROK coast guard.

Chinese diplomats have urged the ROK side to find out the whereabouts of the Chinese citizens as soon as possible, said Hua.

The ministry, the embassy and the consulate general have activated an emergency mechanism, she said, adding that diplomats have been sent to convey sympathies to the families of the missing Chinese citizens.