The Japan Coast Guard says four Chinese government ships entered the country's territorial waters near the Senkaku Islands early on Friday morning.

Coast guard officials say the vessels approached the island of Minamikojima from 2:11 a.m.

The officials say two of the ships had been sailing in the contiguous zone just outside Japan's territorial waters since Thursday night, but they were 20 to 22 kilometers south-southeast of Minamikojima within the territorial waters as of 2:40 a.m.

The other two ships were reported as navigating 19 to 22 kilometers southeast of the island, also within Japan's waters.

The coast guard has been warning the vessels to leave the area.

The Japanese government is monitoring the situation.
This is the 21st time this year and the first since July 19 that Chinese government ships have been spotted in Japan's waters around the Senkaku Islands.

Japan controls the islands. China and Taiwan claim them. The Japanese government maintains the islands are an inherent part of Japan's territory, in terms of history and international law. It says there is no issue of sovereignty to be resolved over them.