"Otherwise, China will take further measures," Wen was quoted as saying by the official Xinhua news agency in New York, where he is due to take part in UN meetings and talks with state leaders including US President Barack Obama.

The dispute erupted when a Chinese fishing trawler and two Japanese coastguard vessels collided on September 7 near disputed islands that lie in rich fishing grounds and near possible oil and gas fields.

Japan arrested the captain, Zhan Qixiong, 41, the following day, citing its domestic law. On Sunday, a court extended his detention until September 29, when he must be either indicted or released. China has reacted furiously to the arrest, repeatedly demanding Zhan be released, summoning Japan's ambassador six times, suspending senior-level exchanges and cancelling several cultural events.

The disputed islands are known as Senkaku by Japan and Diaoyu by China and are also claimed by Taiwan.

AFP