TOKYO (Reuters) - Japanese air force jets are scrambling at a record pace to counter Chinese fighters intruding into its air space along its southern flank and Russian bombers and spy planes probing its northern defenses, the Defence Ministry said on Tuesday.

Chinese fighter flights have increased in and around the energy-rich East China Sea, where Japan and China both lay claim to a group of islets.

In the nine months ending Dec 31, Japanese fighters scrambled 744 times, 32 percent more than the same period the previous year, the ministry said. Encounters with Chinese aircraft, which accounted for half of the nine month total, jumped to 164 in the final quarter of 2014, the most since 1958, when records began.

At the current pace, scrambles for the year to March 31 would exceed the 944 encounters logged 30 years ago at the height of the Cold War.

“With only three quarters of data available, we can’t yet say whether it will be a record year,” a spokesman for Japan’s Air Self-Defence Force told reporters.

In the last three months, Japanese jest scrambled 369 times to meet Russian planes, four times the pace of a decade ago.

Japan’s Hokkaido island to the north of the country’s main land mass lies close to four smaller islands which are claimed both by Japan and Russia. That territorial dispute has prevented Japan and Russia from concluding a formal peace treaty.

The unexpected resurge in overflights by Russian aircraft comes as Japan thins out its forces in Hokkaido in order to focus on what it sees as a more immediate threat posed by an assertive China in the southwest.

Japan is buying Boeing Co Osprey tilt-rotor troop carriers, Lockheed Martin Corp F-35 stealth fighters, BAE Systems Plc amphibious assault vehicles and other equipment as it turns its attention to the vast maritime region bordering Chinese territory.