Japan scrambled its air forces a record 306 times to intercept Chinese aircraft intruding its airspace in 2012, a figure reflecting the tense atmosphere between the two countries amid a tug-of-war over disputed islands.

According to the Defense Ministry, the Air Self-Defense Force dashed jets a total of 567 times in fiscal 2012, with 306 times intended to intercept Chinese aircraft alone, surpassing the number of times it had to deal with Russian aircraft at 248.

“It is obvious China is increasing its aircraft activity,” a ministry official told the Asahi Shimbun. “We will analyze its activities and enhance patrol and surveillance in airspace southwest of Japan”.

Japanese surveillance of its airspace, particularly above disputed islands in the East China Sea, increased as Chinese aircraft was seen hovering near the territories in a what seems to be an effort to challenge Japan’s control of the islands.

Japan scrambled jets to the Senkaku Islands in December after a Chinese state aircraft flew over the area. It was the first time China violated Japanese airspace, the ministry said.