PORTLAND — Portland police are investigating a robbery in which a male wearing a hooded New England Patriots football sweat shirt demanded cash from the clerk.

Lt. Robert Ridge said the suspect walked into the Big Apple convenience store at 1585 Congress St. around 9:15 p.m. Wednesday and pretended to have a weapon hidden inside his clothing.

No weapon was displayed but the clerk handed over an undetermined amount of cash, Ridge said.

A police canine unsuccessfully tracked the suspect, who fled on foot.