A South Korean vessel departed from a port in Busan late Sunday to conduct maritime survey in waters near the disputed islets of Dokdo in the East Sea.

A 2,533-ton vessel with about 20 crew members departed port at around 10:30 PM (13:30 GMT Sunday), the Yonhap News quoted unnamed officials from the National Oceanographic Research Institute as saying.

According to Yonhap, the survey will last from July 3 to July 14.

South Korean government announced on June 1 to carry out research on ocean currents in the waters near the islets of Dokdo, which Japan also claims sovereignty and calls "Takeshima", despite Japan's strong protests.

Japan's Coast Guard warned last month that it would dispatch patrol ships to block South Korea's research ships if South Korea presses forward with the survey plan.

The bilateral ties between Seoul and Tokyo was heavily strained in April when Japan announced to carry out a maritime survey near Dokdo while South Korea strongly warned against it. Japan canceled the plan in late April after the two sides comprised on a pact through diplomatic contact.

In mid-June, South Korean and Japanese diplomats held a two-day negotiation over the exclusive rights to the waters around Dokdo early in Tokyo but failed to make any obvious breakthrough. The two sides agreed to meet again on the issue in September in Seoul to seek a diplomatic solution.

Dokdo, which has been controlled by South Korea since 1950s, lies 90 km southeast of South Korea's Ulleung Island and 160 km northwest to Japan's Oki Island.

(Xinhua News Agency July 3, 2006)