A man struck a woman twice in the head with a handgun and stole her purse Tuesday night on East Michigan Avenue, then fired a shot as a man was chasing him down, Ypsilanti police said.

Police continue to investigate the robbery at 10:49 p.m. in a gas station parking lot near the intersection of East Michigan Avenue and Prospect Street.

So far, no arrests have been made. Detectives said they are reviewing surveillance video from the gas station as they attempt to identify the robber.

According to police, a 26-year-old Ypsilanti Township woman attempted to open the door to the gas station convenience store and returned to her car after realizing the store was closed. That's when a young man opened her car door, demanded her purse and struck her on the forehead and cheek with a silver handgun, Det. Sgt. Troy Fulton said.

The man took her purse and ran, Fulton said. A delivery man who didn't witness the robbery, but knew something was wrong, began chasing the robber, Fulton said. According to Fulton, the robber fired a shot, but no one was hit.

The robbery victim refused medical attention, police said. The robber was described as black, between 5 feet, 10 inches and 6 feet tall, with a very dark complexion, police said. He was wearing a puffy mustard yellow-colored jacket.

Anyone with information can call police at (734) 483-9510.

Lee Higgins covers crime and courts for AnnArbor.com. He can be reached by phone at (734) 623-2527 and email at leehiggins@annarbor.com.