Japan on Thursday summoned the Chinese ambassador, as the two sides traded accusations of blame for a near miss involving fighter jets over the East China Sea, the second similar incident in less than a month.

In the latest confrontation in a long-running territorial dispute, Tokyo says two Chinese SU-27 jets flew as close as just 30 metres to its aircraft in a spot where the two countries' air defence zones overlap.

"It was an action that was extremely regrettable, and which cannot be tolerated," said top government spokesman Yoshihide Suga, of the Wednesday incident.

It was the second time in less than three weeks that Tokyo has accused Beijing of playing chicken in the skies near the hotly contested Japanese-controlled Senkaku islands, which China also claims and calls the Diaoyus.

"It comes after a similar event which occurred last month," Suga said. "The government will continue urging China to prevent an accident and restrain itself."

Japan's vice minister for foreign affairs, Akitaka Saiki, called the Chinese ambassador to Japan, Cheng Yonghua, to the ministry, where he said similar manoeuvres "could lead to a real accident", according to Kyodo News.

China hit back, insisting Japanese pilots had been at fault and that Tokyo was lying to the international community about China's behaviour.

"Japan has hyped the claim that a Chinese fighter flew 'unusually close' to a Japanese surveillance plane, exaggerating China's military threat," said a statement on the Chinese defence ministry website.

"The Chinese pilot's operation was professional, standard and maintained restraint. The Japanese pilot's practice was dangerous, and obviously provocative in nature."

Foreign ministry spokeswoman Hua Chunying said Japan has "ignored the facts" and "hyped up this incident and the so-called China threat".

"(Japan has) deliberately deceived the world. So we can't help but wonder what is the true intention of Japan."

The website also carried video footage of another incident in which two Japanese F-15 jets approached a Chinese TU154 plane on Wednesday, saying the near-miss disrupted its safe flight.

Japan's Defence Minister Itsunori Onodera said he saw the video himself.

"There was no truth behind what the Chinese side stated," he told reporters. "The self-defence force aircraft were flying stably at a certain distance."

"China may have gone out of its way to release the video as they may feel something shameful about the case in which Chinese fighter jets approached (Japanese) self-defence force aircraft," Onodera said.

- Political alliances -

The incident occurred as Japan and Australia held the fifth round of so-called "2+2" talks between their defence and foreign affairs chiefs in Tokyo.

The meeting was in line with a trend towards strengthening and political alliances in the Asia-Pacific, as countries look with alarm at China's willingness to forcefully push its claims in territorial disputes.

The two sides reached a broad agreement on a legal framework to allow them to conduct joint research and trade in defence equipment.

Japanese Prime Minister Shinzo Abe has relaxed strictures on his country's arms industry to allow it to sell its high-tech weaponry abroad, and as Canberra is known to be shopping for submarines.

Abe bills Japan as a benign counterweight for countries looking askance at China's recent heavy-handedness, which has led it to become embroiled in destabilising rows with Vietnam and the Philippines.

Japan's own dispute with China is heavily coloured by differences over shared history, but is being played out on the seas and in the skies near the Senkakus, where boats and planes have sparred for nearly two years.

Few observers believe there will be an outright military conflict over the uninhabited islands, but many warn that with so much hardware in the area, the greatest risk is of an accidental collision.

They say that any crash could quickly spiral into a confrontation that would see local commanders taking decisions under pressure that could have huge geo-political implications.