(VOVworld) – Japan’s Maritime Self-Defense Force on Monday spotted 3 Chinese patrol vessels entering Japanese waters near the disputed Diaoyu/Senkaku Islands in the East China Sea.

A Chinese ship is seen near the disputed Senkaku/Diaoyu islands in the East China Sea (Photo: AFP/ VNA)

The vessels were said to have remained there for 90 minutes before leaving. Earlier, the Chinese aircraft carrier Liaoning was detected in the East China Sea for the first time. The Liaoning, China’s first aircraft carrier, was accompanied by 3 guided missile destroyers, 3 frigates, and 1 supply ship. China’s Xinhua News Agency reported that a Chinese fleet including the Liaoning was heading to the western Pacific Ocean for a routine training exercise. The disputed Diaoyu/Senkaku Islands, currently controlled by Japan, are located about 400 kilometers from the main Japanese island of Okinawa. China also claims sovereignty over the islands and has frequently sent ships and planes to its territorial water. Relations between Japan and China have grown tense over the years due to the dispute over the islands, especially after Tokyo decided to nationalize 3 of 5 islands there in September, 2012.