Japan's coastguard said on Tuesday it had arrested the captain of a Chinese fishing boat operating illegally in territorial waters, but Beijing indicated it did not expect a flare-up over the case ahead of visit by the Japanese prime minister.

Ties between the two countries deteriorated sharply last year following the detention of the captain of a Chinese trawler that collided with Japanese patrol boats near disputed islets in the East China Sea.

The latest arrest also comes as Prime Minister Yoshihiko Noda is scheduled to visit Beijing for a bilateral summit on December25-26. But the Chinese foreign ministry indicated that it saw no cause for a diplomatic flare-up.

We're now investigating the situation, ministry spokesman Liu Weimin told a daily news briefing in Beijing.

Liu called it an ordinary case and said: China hopes that the Japanese side will protect the legitimate rights of the Chinese captain and handle this matter appropriately.

Japan's coastguard said it seized early on Tuesday a 130-ton Chinese boat about 87 km (54 miles) from an island off Nagasaki Prefecture in southern Japan, and arrested the captain, Zhong Jinyin, 39.

The boat, with the captain and 10 sailors on board, tried to flee when it was found operating near the island late on Monday evening, ignoring a Japanese patrol boat's order to stop, the coastguard said.

It was captured at around 5:00 a.m. (2000 GMT Monday). There were no reports of injury.

Chinese fishing boats are frequently caught fishing in South Korean waters, sometimes leading to violent clashes with South Korean maritime police.

Last week, a South Korean coastguard was stabbed to death by a Chinese fisherman in an operation to apprehend a Chinese vessel operating illegally near South Korean waters, fuelling anger among Koreans.

(Reporting by Tetsushi Kajimoto; Additional reporting by Chris Buckley in Beijing Editing by Joseph Radford and Ed Lane)