Japan's defense minister said the use of flares was a legitimate response to airspace violation and "we plan to use it without hesitation."

Japan says its warplanes used flares to warn a Russian reconnaissance aircraft to leave northern Japanese airspace.

Japan scrambled fighter jets after a Russian Il-38 plane entered Japanese airspace on Sept. 23. Japan used flares after the Russian plane ignored earlier warnings, Japanese Defense Minister Minoru Kihara said.