On Monday, a Russian military patrol aircraft entered Japanese airspace near Hokkaido’s Rebun Island on three separate occasions. In response, Japan’s Self-Defense Force (SDF) scrambled aircraft and fired flares as an emergency measure.

This marks the first time the SDF has fired flares in response to an airspace violation, according to a statement to reporters.

During the third incursion, SDF fighter jets, including F15s and F35s, issued radio warnings to the Russian military before firing the flares, Defense Minister Minoru Kihara said.

The Japanese government has lodged a protest through diplomatic channels and demanded that Russia prevent similar violations in the future.