BERLIN (AP) — Authorities in Austria said Thursday that a police firearms instructor is being investigated for accidentally shooting dead a fellow officer during a training exercise.

Prosecutors in the southern city of Graz said the 39-year-old instructor had handed practice weapons to the officers, but forgotten that he was still carrying his own service firearm.

Intending to show the group that one them was standing in a dangerous position, the instructor drew his gun and shot the 27-year-old officer in the back at close range, wounding him fatally.

Christian Kroschl, a spokesman for the prosecutors office, said there was no doubt the incident Wednesday had been an accident.

The instructor is now being investigated on suspicion of grossly negligent killing, he said.