Japan’s Coast Guard sent its own patrol ships to the region and asked Chinese ships to leave Japan’s territorial waters immediately, it said.
Such infiltration is not uncommon in the disputed area. Tokyo and Beijing both lay claim to the uninhabited islands, but Japan has administered them since 1972. Taiwan, which Beijing considers a Chinese province, also claims ownership of the islands.
Chinese officials have repeatedly said that it is China’s inherent right to patrol the waters around the islands. China’s foreign ministries and national defense ministries did not immediately respond to requests for comment on the Japanese Coast Guard’s statement on Friday.
The Japanese coast guard said the latest incursion marked the longest time spent by Chinese government ships in the waters since 2012, when Tokyo bought some of the islands from a private Japanese owner.
The longest incursion before this happened in October 2020, when a Chinese vessel was stalled for more than 57 hours.
The latest example comes amid growing friction between the two neighbours, especially as China is cautious about Japan’s ties with the United States.
Last month, Tokyo hosted a summit for the increasingly active Quad Security Group, made up of Japan, the United States, Australia and India. Beijing sees the group as part of US efforts to control it.
Hours after the end of the summit, Chinese and Russian air forces conducted joint strategic air patrols over the Sea of Japan, the East China Sea and the western Pacific Ocean, which the Chinese Defense Ministry called part of the annual military cooperation plan.
The ministry said the group has been operating at sea near Japan since June 12.