The China Coast Guard expelled four Japanese fishing boats that entered territorial waters near the Diaoyu Islands from Friday to Monday, a spokesman said.

China Coast Guard spokesman Liu Dejun said in a statement late Monday that Chinese vessels took "necessary control measures" and warned the Japanese boats to leave.

The Diaoyu Islands are China's inherent territory, Liu said.

"We urge the Japanese side to immediately cease all illegal activities in these waters," Liu said.

He added that the China Coast Guard would continue its patrols to safeguard China's territorial sovereignty and maritime rights.