Superior police searching for armed robber

Superior police are searching for a man who robbed a Super America gas station early Tuesday morning.
Police were called to a silent alarm at the station, 1405 Broadway Street, just before 5 a.m. A female clerk reported that a man was paying for some items when he jumped over the counter and punched her in the face. He appeared to be holding a weapon in one hand.
Surveillance video of the incident released by police shows the man producing what appears to be a pocket knife and leaping over the counter. The video shows him throwing several punches at the woman, who runs away. After an unsuccessful attempt to reopen the cash register, which was knocked shut during the skirmish, the man runs out of frame.
Police said a witness attempted to block the doors, but the suspect produced the weapon and threatened the good Samaritan. The suspect was last seen getting into a car that was determined to have been stolen in Duluth.
The suspect is described as a black male, approximately 5 feet, 5-7 inches tall, weighing 150-160 pounds. He appeared to be wearing a black hooded sweatshirt, dark pants and a winter cap during the robbery.
Anyone with information about the incident is asked to contact the Superior Police Department.