China confirmed Thursday that a fleet of ships from the China Coast Guard (CCG) recently patrolled the country's territorial waters surrounding the Diaoyu Islands.
"The Diaoyu Island and their affiliated islets are an integral part of Chinese territory and have been since ancient times," said Chinese foreign ministry spokesperson Hong Lei, while adding that the patrols were designed to exercise China's inherent sovereignty, Xinhua reported.
As the CCG fleet patrolled the waters, they spotted a Japanese vessel, believed to belong to a right-wing Japanese politician, illegally sailing there, he said.
Hong said the Chinese foreign ministry and the Chinese embassy in Tokyo have respectively lodged solemn representations and expressed strong protests to the Japanese side.
The Japanese vessel has already left the Chinese territorial waters, he added.
The islands are called "Diaoyu" in China but "Senkaku" in Japan. The row over the islands, which are presently controlled by Japan, has left ties between Tokyo and Beijing highly tense.
Japan claims to be occupying the islands since 1895, while China maintains the islands were recognised as Chinese territory as early as 1783.
