CALUMET CITY | A gunman shot a mailman Wednesday afternoon in Calumet City, and the federal government is offering a $25,000 reward for information leading to arrest and conviction.

The mail carrier was treated for a bullet wound to the leg after the gunman tried to rob him at 4 p.m. at Hoxie and Wilson avenues, near Torrence Avenue and Sibley Boulevard, said Postal Inspector Paul Krenn.

Officers on Wednesday night were following leads and knocking on doors looking for the shooter. Krenn -- a Chicago-based federal agent -- worked from the Calumet City police station Wednesday night. Shooting a postal worker is a federal offense.

The gunman approached the uniformed mailman as the mailman drove a vehicle, Krenn said. The gunman had drawn his gun when the mailman got out of the vehicle, and the man shot him in the leg with a small revolver, Krenn said. The gunman appeared interested in robbing the mailman, not stealing mail, Krenn said.

The only description Krenn could offer was: a black man between 17 and 19 years old, between 5'7" and 5'9" and wearing a long white T-shirt.