This bird eye view shows the coral reefs in China's Xisha Islands, South China Sea, June 1, 2011. (Photo: Xinhua)

The People's Liberation Army Southern Theater Command expelled a United States warship on Thursday for trespassing into Chinese territorial waters of the Xisha Islands in the South China Sea.

The US guided missile destroyer USS Mustin trespassed into the waters on Thursday and the PLA Southern Theater Command dispatched naval and air forces to track, identify and warn it to leave, Senior Colonel Li Huamin, the theater command's spokesman, said in a statement on early Friday.

The US has ignored the international law, and repeatedly stirred up trouble in the South China Sea under the pretense of "freedom of navigation", Li said. These actions have seriously undermined China's sovereignty and security interests, as well as order in the region, he added.

"We urge the US to stop such provocative actions and strictly manage the activities of its naval and air force assets and personnel to avoid possible military accidents," he said.

"China has undisputable sovereignty over the islands in the South China Sea and their adjacent waters in the region," he said. "The troops are always on high alert to resolutely safeguard national sovereignty, as well as peace and stability in the South China Sea."

Also on Thursday, a P-8A reconnaissance aircraft flew into China's air defense identification zone in the East China Sea and approached the northern part of Taiwan before flying eastward, according to the South China Sea Strategic Situation Probing Initiative, a Chinese nonprofit research institution.

On Wednesday, the local maritime authority in Zhejiang province said the Chinese military would conduct "real weapons training" in the East China Sea from Thursday to Sunday, and prohibited ships from entering the training area.

Senior Colonel Wu Qian, spokesman of the Ministry of National Defense, said at a news briefing on Thursday that China recently held military drills in the waters and airspace around the Nansha and Xisha islands in the South China Sea, as well as in waters off Qingdao, Shandong province, and Lyushun, Liaoning province.