BEIJING, March 18 (Xinhua) -- Chinese marine surveillance ships continued regular patrols in the territorial waters surrounding the Diaoyu Islands on Monday, the State Oceanic Administration said.

A fleet consisting of the Haijian 137, Haijian 15 and Haijian 8002 solemnly declared to Japanese ships that the Diaoyu Islands have been Chinese territory since ancient times and urged them to immediately leave the Chinese waters, the statement said.