Australia has protested to Beijing that a Chinese fighter jet endangered an Australian navy helicopter with flares in international waters, officials said Monday.

The incident occurred on Saturday as the Australian air warfare destroyer HMAS Hobart was enforcing United Nations Security Council sanctions against North Korea in international waters in the Yellow Sea, the Defense Department said in a statement.

A Chinese Chengdu J-10 fighter jet released flares in the flight path of an Australian navy Seahawk deployed from the Hobart 300 meters (986 feet) in front of the helicopter and 60 meters (197 feet) above, Defense Minister Richard Marles said.

“This was an incident which was both unsafe and unprofessional,” Marles told Nine News television.