A ship with nine crewmen capsized in disputed waters off South Korea's easternmost islets of Dokdo, or Takeshima in Japan, Yonhap news agency reported Wednesday, citing the country's coast guard.

The coast guard was informed by the Japanese authorities that a 72-tonne ship tipped over at about 2:24 p.m. local time (0524 GMT) in international waters some 168 km northeast of the Dokdo islets.

Four Chinese, two Indonesian and three South Korean crewmen were aboard the ship, Yonhap said.

The nine crewmen were still unaccounted for and the coast guard reportedly dispatched two patrol ships and a helicopter for search operations. 

(With input from Xinhua)