TOKYO - Japan scrambled fighter jets Saturday as Chinese air force planes passed the Miyako Strait in Okinawa Prefecture, southwestern Japan, the Defense Ministry said.

Six Chinese airplanes believed to include two fighters flew over the strait between Okinawa's main island and Miyako Island, according to the ministry.

There was no actual infringement of Japanese territorial air space, it said.

A similar incident occurred in September in the area when eight Chinese airplanes including fighters passed over the strait, prompting an alert by the ministry. It was the first such passage through the area by Chinese military aircraft.

According to the ministry's Joint Staff Office, four airplanes including H-6 bombers and intelligence-gathering aircraft flew northwest in the Pacific Ocean toward East China Sea, passing over the Miyako Strait.

Two Su-30 fighter jets that passed the strait from the opposite direction made u-turns to join the four other aircraft before flying to the East China Sea, the ministry added.