Three Chinese coast guard ships temporarily entered Japanese territorial waters around the disputed Senkaku Islands in the East China Sea on Sunday, the Japan Coast Guard said.
The intrusion was the first since Japanese Prime Minister Shinzo Abe's controversial visit to the war-linked Yasukuni Shrine in Tokyo on Thursday and was the 74th day since Japan purchased some of the uninhabited islands from a private Japanese owner in September last year, according to the 11th Regional Coast Guard Headquarters in Naha, Okinawa Prefecture.
The last time Chinese vessels entered what Japan calls its territorial waters was Dec. 22.
The Senkaku group is administered by Japan but claimed by China and Taiwan, which call the islands Diaoyu and Tiaoyutai, respectively.
Meanwhile, the China's State Ocean Administration in Beijing said Sunday the Haijing 2112, 2151 and 2337 operated in what it calls its waters.
Junichi Ihara, head of Foreign Ministry's Asian and Oceanian Affairs Bureau, lodged a protest by phone with Han Zhiqiang, minister at the Chinese Embassy in Tokyo, and demanded the immediate exit of the ships. All the ships exited the territorial waters by 5 p.m., the coast guard said.
Han claimed China's sovereignty over the islands and said he will relay the protest to the Chinese government, according to the Japanese Foreign Ministry.