Japanese fighter jets fired warnings flares against a Russian military aircraft that Tokyo said repeatedly entered the country’s territorial airspace, in an unprecedented move against a foreign plane.

For the first time in 60 years, Japanese fighter jets fired warning flares at a Russian reconnaissance aircraft that violated Japanese airspace, reports The Wall Street Journal. On Monday, the Russian Ilyushin Il-38 reconnaissance aircraft violated it three times.

Russian patrol aircraft were intercepted by Japanese fighter jets after Moscow's planes violated the Western-ally's airspace, Tokyo has said.