Four Chinese marine surveillance vessels patrolled territorial waters around the Diaoyu Islands on Friday, according to the State Oceanic Administration (SOA).
The fleet declared the Chinese government's stance regarding the Diaoyu Islands to Japanese ships that had illegally entered the waters, the SOA said.
The four vessels asked the Japanese ships to leave the waters and collected evidence of infringement on China's sovereignty, it said.
Copyright ©1999-2011 Chinanews.com. All rights reserved.
Reproduction in whole or in part without permission is prohibited.