BEIJING — China has suspended senior bilateral contact with Japan over the detention of a Chinese captain accused of ramming his boat against Japanese patrol vessels in disputed waters, state media said Sunday.

"China has already suspended bilateral exchanges at and above the provincial or ministerial levels," the official Xinhua news agency quoted the foreign ministry as saying, without giving more details on the nature of the exchanges.

China has also halted contact with Japan on the issues of increasing civil flights and expanding aviation rights between the two countries, the report said, adding a bilateral meeting on coal had also been postponed.

The stringent measures come after a Japanese court authorised prosecutors to extend by 10 days the detention of Zhan Qixiong, arrested earlier this month after the collision with two Japanese coastguard vessels in the East China Sea.

The incident took place near the disputed Diaoyu islands -- called Senkaku in Japan 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 diplomatic row in years between Beijing and Tokyo, with China already summoning Japan's ambassador five times and scrapping scheduled talks over joint energy exploration in the East China Sea.

Chinese Premier Wen Jiabao and his Japanese counterpart Naoto Kan risk an embarrassing crossing of paths this week when they both attend a UN meeting in New York, where each is separately scheduled to meet US President Barack Obama.

Japan suspects Zhan deliberately rammed its patrol boats, and has held him citing domestic law, although it has released his crew and boat.

Foreign ministry spokesman Ma Zhaoxu threatened Japan with "serious counter-measures" if the captain was not released, reiterating Beijing's stance that the detention was "illegal and pointless".

"We ask Japan to immediately and unconditionally release the Chinese captain," he said in a statement.

The incident has sparked resentment among the Chinese public, which still has strong feelings about atrocities committed by Japanese forces when they occupied swathes of northern China before and during World War II.

On Saturday, the anniversary of Japan's 1932 invasion of Manchuria, protesters rallied in Beijing, Shanghai and Hong Kong, although the demonstrations were relatively small, short and non-violent.