Campus police at the University of Michigan are investigating an alleged early-morning assault at UM's Nichols Arboretum in Ann Arbor.

Campus police say that at about 1:30 a.m., a man was sitting on a bench in the Arb near the peony gardens. Then the man heard something behind him, and as he turned around, he was hit in the right eye with a glass bottle.

The victim told police that the suspect pulled out a "plastic airsoft-type pistol," put it up to his neck, and told him to not move.

But the victim did move, punching the suspect, who fell to the ground. The victim used the opportunity to flee.

Campus police describe the suspect a man 5 feet-10 inches to 6 feet tall, with tattoos visible on both forearms. He wore blue jeans, a red hoodie, and a white shirt underneath.