Japan lodged a protest with China on Saturday after three Chinese government ships continued to patrol Diaoyu Islands in the East China Sea.
Kanji Yamanouchi, deputy director general at the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, lodged the protest over the phone with Guo Yan, minister-counselor at the Chinese Embassy in Tokyo, according to the Kyodo news agency.
Yan said the Chinese side cannot accept Japan's allegation.
China's Xinhua News Agency said a fleet of three Chinese marine surveillance ships continued to patrol territorial waters off China's Diaoyu Islands Saturday, according to the State Oceanic Administration (SOA).
The vessels are Haijian 137, Haijian 23 and Haijian 26, the SOA said in a statement
A Japan Coast Guard vessel had ordered the Chinese ships to leave the waters, but one of them said the islets "have been inherent territories of China since ancient times," according to the 11th Regional Coast Guard Headquarters in Naha, Okinawa Prefecture.