The command said several Japanese vessels entered the waters of China's Diaoyu Islands earlier in the day, while Chinese coast guard vessels took the necessary control measures in accordance with the law and warned the Japanese ships to leave the said waters.
"We call on Japan to immediately stop all illegal activities in the said waters and ensure that such incidents never occur again," it added.
China and Japan continue to have a territorial dispute over the Senkaku Islands. After World War II, the islands were controlled by the United States and then handed over to Japan in 1972. Beijing disagrees with the decision, recalling that the islands were marked as Chinese territory on Japanese maps from 1783 and 1785. The conflict escalated in 2012 after the Japanese authorities bought out five islands from a private Japanese owner.