Two Chinese government ships intruded into Japan's territorial waters near the Senkaku Islands in the East China Sea early on Friday, apparently following two Japanese fishing boats. The same Chinese ships had also entered the territorial waters on Thursday.
The Japan Coast Guard says the two Chinese ships entered the territorial waters off Taisho Island between 4:20 a.m. and 4:50 a.m. on Friday.
Coast guard officials said the ships and two other Chinese vessels had previously been sailing in the contiguous zone just outside Japan's territorial waters.
As of 5 a.m., the two ships were spotted about one to five kilometers from the Japanese fishing boats that were 16 kilometers southwest of Taisho Island.
The coast guard dispatched patrol vessels to ensure the safety of the fishing boats and to warn the Chinese vessels to leave Japan's territorial waters immediately.
On Thursday, the Chinese ships, along with two others, intruded into the territorial waters near Uotsuri Island, and were also apparently following Japanese fishing boats. The ships remained within the territorial waters for about 17 hours.
Friday's incident is the ninth time this year that Chinese government ships have been spotted in Japan's territorial 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.