Japan has asked China to call back two patrol vessels from disputed islands in the East China Sea, the Jiji news agency quoted a government spokesman as saying on Monday.
The Chinese boats have been there since Friday, Yoshito Sengoku told a news conference.
A collision between a Chinese trawler and two Japanese patrol vessels on September 7 near the uninhabited islands, known as the Senkaku islands in Japan and the Diaoyu islands in China, has led to the worst diplomatic spat between the two countries in years.
Neither Tokyo nor Beijing have apologized for the incident as both countries claim the islands, believed to hold oil and gas deposits, as part of their territories.
Tensions were further exacerbated on Friday, when China said its police had detained four Japanese men for filming in a military zone.
MOSCOW, September 27 (RIA Novosti)