China says it placed buoys near islands disputed with Japan to monitor ocean conditions

China says buoys placed near disputed islands in the East China Sea are for monitoring ocean conditions.

Foreign Ministry spokesman Hong Lei told reporters at a briefing Tuesday that the presence of the buoys should not be "disputed or played up."

Japan had earlier asked China to explain the purpose of the buoys, which were placed just outside Japanese waters near the uninhabited islands called Senkaku by Japan and Diaoyu by China. Some in Japan had speculated that the buoys were intended to detect the movement of submarines.

The long dispute between China and Japan over the islands flared anew after Japan purchased three of the group from their private owners in September. Beijing says the islands have been Chinese for centuries, but Japan refuses to acknowledge any counterclaims.