A Japanese court on Sunday authorised prosecutors to extend by 10 days the detention of a Chinese captain for ramming his trawler against Japanese patrol boats near disputed islands, reports said.
China has been calling for the immediate release of the captain, Zhan Qixiong, 41, who was arrested on September 8, the day after the collision with two Japanese coastguard vessels in the East China Sea.
Zhan's initial detention on suspicion of obstructing official duties was set to end on Sunday.
The extension was reported by the Jiji and Kyodo news agencies but there was no one immediately available at the court on Ishigaki island in the Okinawan chain to confirm the reports.
The incident took place near the uninhabited islands -- called Senkaku in Japan and Diaoyu in China, and also claimed by Taiwan -- which lie in an area with rich fishing grounds that is also believed to contain oil and gas deposits.
It has sparked the worst tensions between the Asian neighbours in years, with Beijing summoning Tokyo's ambassador five times in a week and scrapping scheduled talks over joint energy exploration in the East China Sea.
His crew and ship were taken to Ishigaki but the 14 other crew members were sent home last Monday after investigations.
China said Sunday it could take "strong measures" against Japan after Tokyo extended the detention of a Chinese captain for ramming his trawler against Japanese patrol boats near disputed islands.