a Japanese Coast Guard boat and vessel sail alongside Japanese activists' fishing boat, not in the photo, warning the activists away from a group of disputed islands called Senkaku by Japan and Diaoyu by China on Aug. 18, 2013 (AP)

In a recent incident in the contested waters around the Diaoyu Islands, also known as the Senkaku Islands, the Chinese coastguard reported that its vessels issued warnings to Japanese ships they deemed to have "illegally intruded" into the area on Tuesday.

The Chinese coastguard asserted that its vessels took "necessary control measures" in response to the alleged intrusion, though specific details were not provided. As of now, there has been no response from Japanese authorities regarding the incident.

In response to the violation, China has called on Japan to cease all "illegal activities" in the disputed waters and ensure that similar incidents do not happen in the future, according to a statement from the Chinese coastguard.

In previous confrontations, Chinese Foreign Ministry spokesperson Zhao Lijian has defended its activities in the vicinity saying "Diaoyu Dao and its affiliating islands have been part of China’s territory. The activities of Chinese vessels in the adjacent waters are legitimate and lawful. The Japanese side has no right to point fingers over these activities".

The origins of the dispute

The Diaoyu Islands are the subject of expanded territorial claims from China and Japan. China cites Japanese maps from 1783 and 1785 that show the islands as being in Chinese territory, whereas Japan argues that its rule over the islands has been in place since 1895. The Diaoyu Islands came under US administration following World War II before being transferred to Japan in 1972.

Japan thinks that China's claims to sovereignty over the islands stem from the 1970s discovery of lucrative minerals in their shelf waters. When the Japanese government acquired three of the five islands from a private owner in 2012, the territorial issue intensified.

This dispute has led to repeated confrontations with both nations deploying patrol boats and issuing calls for the other to vacate the area.