An off-duty school police officer was critically wounded in a shooting at a gas station near the Philadelphia Zoo Wednesday night, city police said.

The officer was transported by city police to the Hospital of the University of Pennsylvania, where he was listed in critical but stable condition. The shooting was reported at 11:14 p.m. in the area of a Sunoco station at 3750 W. Girard Ave., police said. A clerk at the station said the shooting victim had purchased antifreeze before the shooting. Police said the assailant fled east on Girard in a green Chevrolet Venture minivan. - Bob Moran