Tokyo: Japan protested to Beijing on Wednesday after Chinese fighter jets flew within 30 metres of Japanese military planes in airspace claimed by both nations. Similar fly-bys in the same area took place several weeks ago.

In two separate episodes on Wednesday, Chinese Su-27 fighters flew dangerously close to two Japanese propeller-driven reconnaissance planes in skies over the East China Sea, Japan's Defence Ministry said.

The latest incident involved a Su-27 jet fighter, similar to this one. Credit:Reuters

The fly-bys are the latest escalation in an increasingly tense test of wills between China and Japan for dominance of the East China Sea, which includes a group of uninhabited islets that both nations claim. Japan took control of the island group when it was a rising imperial power in the late 19th century, but now a newly resurgent China wants to regain what it sees as stolen territory.

The ministry said the Japanese planes had returned safely to base, though the faster Chinese jets came close enough that the crew of one Japanese craft photographed what appeared to be white missiles on the underside of the jets.