TOKYO Two Chinese marine surveillance ships entered what Japan considers its territorial waters near disputed islands in the East China Sea on Monday, the Japanese Coast Guard said, a move bound to raise tension between Asia's two largest economies.
China's Xinhua news agency confirmed that two civilian surveillance ships were undertaking a "rights defense" patrol in waters near the disputed islands, citing the State Oceanic Administration, which controls the ships.
Sino-Japanese relations deteriorated sharply after Japan bought the islands, called Senkaku in Japan and Diaoyu in China, sparking anti-Japan protests in cities across China.
"In recent days, Japan has constantly provoked incidents concerning the Diaoyu islands issue, gravely violating China's territorial sovereignty," China's Xinhua news agency said.
The ship patrols were intended to exercise China's "administrative jurisdiction" over the islands, it said.
The Japanese Coast Guard ordered the Chinese ships to move out of the area, but received no response, a coast guard official said.
Sino-Japanese ties have long been plagued by China's bitter memories of Japan's military aggression in the 1930s and 1940s and present rivalry over regional influence and resources.
The islets are located near rich fishing grounds and potentially huge gas reserves.