TOKYO (AP) — Tokyo has lodged protests to Beijing over the entry of Chinese coast guard ships into Japan's territorial waters off disputed East China Sea islands and their refusal to move out for a third day Tuesday, Japanese officials said.

The two Chinese ships entered the Japanese-claimed waters Sunday morning, appearing to approach a Japanese fishing boat carrying three crew members. They have remained there, ignoring repeated warnings and exit demands by the Japanese side, Japanese coast guard officials said.

Chinese coast guard vessels routinely violate territorial waters around the Japanese-controlled southern islands of Senkaku, which China calls Diaoyu and also claims.

Chief Cabinet Secretary Katsunobu Kato said Tuesday that it was “extremely regrettable” that the two Chinese coast guard ships were still in Japanese waters. Japan “strictly protested” to the Chinese side and demanded that the Chinese ships immediately move out of Japanese waters, Kato said.

He said Japan would firmly defend its territorial waters, land and airspace “with a sense of urgency."

Japanese coast guard officials said the fishing boat with the three crew members was safely protected, but declined to give any other details.

China's “continuous attempt to change the status quo by force” in the East China Sea where Chinese warships routinely operate and its repeated intrusion into the Japanese waters despite Tokyo's protests is intolerable, Defense Minister Nobuo Kishi said.

"But when it comes to the situation surrounding the Senkaku islands, we have to respond calmly in order not to escalate tensions,” he said. “We urge China to use self-restraint on any action that would escalate tensions.”

The Japanese government says Japan has had ownership of the islands since the late 1890s under international law. Tokyo also says Beijing started claiming its ownership around 1970 when possible undersea oil deposits near the islands were reported.

Japan sees China’s military development and increasingly assertive stance in the East and South China seas as a major security threat. Japan’s military invasion of China in the 1930s and 1940s remains a sore spot between the two sides.

At a daily briefing Tuesday in Beijing, Chinese foreign ministry spokesperson Zhao Lijian reasserted China’s claim to the islands.

“Diaoyu island and its affiliated islands are China’s inherent territory,” Zhao said. “It is China’s inherent right to carry out maritime patrols to enforce the law in the waters surrounding the Diaoyu islands, which Japan should earnestly respect.”

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