Source:
BBC Six Chinese surveillance ships briefly entered waters around islands claimed by both Japan and China, amid a bitter territorial dispute.
China said the ships were carrying out "law enforcement" to show jurisdiction over the islands, called Diaoyu in China and Senkaku in Japan.
Three vessels left after a short time and the other three have now also left, the Japanese coast guard said.
The move came after Japan sealed a deal to buy three of the islands.
Read more:
http://www.bbc.co.uk/news/world-asia-china-19595490 
