NORWALK - Norwalk police are investigating an early morning robbery at a 7-Eleven on Main Avenue.

Authorities say a man who claimed to have a gun threatened a clerk, who turned over a large amount of cash. The robbery occurred just after 4 a.m.

The police K-9 unit used a napkin that the robber touched and left behind to follow his path. Officials say the dogs lost the suspect's trail along the tracks near Jefferson Street.

Police say they have several leads and are asking anyone with information to call them at 203-854-3000.