Chinese ships in disputed waters amid tension with Japan

(File photo)

Tokyo: Four Chinese ships were spotted Sunday in disputed East China Sea waters, Japanese officials said, as Tokyo considered disclosing video footage and pictures as evidence of a Chinese frigate's alleged radar-lock incident.

For the first time after Tokyo made the allegation last week, China sent maritime surveillance vessels near Japanese-controlled islands in the East China Sea, known as Senkaku in Tokyo and Diaoyu by Beijing, which also claims them.

They were seen sailing in the contiguous waters near one of the outcrops as of 0000 GMT, the Japan Coast Guard said.

Tokyo accused a Chinese frigate of locking its weapons-tracking radar on a Japanese destroyer -- the first time the two nations' navies have locked horns in the territorial dispute that has provoked fears of armed conflict breaking out between the two.

Japan's Prime Minister Shinzo Abe on Friday demanded Beijing apologise and admit to the incident, which occurred late January, after Chinese authorities flatly denied Tokyo's accusation.

Japan's Defence Minister Itsunori Onodera said on Fuji TV on Sunday that Tokyo was carefully studying whether or how to disclose military data as evidence.

However he also said he did not think China would "admit to it even if Japan discloses a variety of evidence, because it is trying to protect its national interest".

Onodera on Saturday told the Yomiuri Shimbun newspaper that Tokyo had "evidence to show the fire-control radar chased after the ship (of Japan's Self-Defence Forces) for some time. The visual evidence would convince many of those who watch it".

The long-running row over the islands intensified in September when Tokyo nationalised part of the chain, triggering fury in Beijing and huge anti-Japan demonstrations across China.

Beijing has repeatedly sent ships and aircraft near the islands and both sides have scrambled fighter jets, though there have been no clashes.