Vessels of the marine surveillance fleet – Haijian 51, 23 and 5001 – are patrolling waters near the Diaoyu Islands on Thursday, the State Oceanic Administration said in a statement.

The fleet declared the government’s stance regarding the Diaoyu Islands to Japanese ships that had illegally entered the waters and asked them to leave the waters immediately, the statement said.

China has patrolled the waters near the islands since September when Tokyo illegally "purchased" three of the islands. The State Oceanic Administration will release details of the ongoing patrol to the public on its website.

China’s Ocean Development Report said the possibility of conflict between China and Japan over the islands is increasing.