Police are investigating a robbery reported early Thursday when a man was struck across his face with a hard blunt object while he was sleeping under a tree at Library Park in Lahaina.

Lahaina patrol officers were assigned to investigate at 12:26 a.m.

After hitting the victim, the robber stole the victim’s backback from beneath his head and fled through Campbell Park and Wharf Cinema Center, where the victim lost sight of the other man, police said.

The victim suffered a small laceration to his forehead and refused medical treatment.

The suspect was described as 5-foot-8 to 5-foot-10 inches tall with a medium build. He was wearing shorts, a T-shirt and a baseball cap.

An investigation is continuing, police said.