PHILADELPHIA (CBS) -- Police are investigating a shooting on Interstate-95 North near Columbus Boulevard in Philadelphia. 

Traffic is back flowing on both sides of I-95 near the Columbus Boulevard exits after the northbound side was closed following reports of a shooting Monday afternoon. 

Pennsylvania State Police say a driver called 911 to report another driver fired multiple shots at them, which led to gridlock traffic. 

Police were directing all traffic off the interstate for a period of time, but the highway has since reopened. 

PSP say just before 1:30 p.m. a driver called 911 saying a person on a motorcycle fired several rounds from a handgun into their car. 

Chopper 3 captured a line of officers walking down I-95, looking for shell casings. 

Officers were also seen looking around a gold minivan stopped on I-95. 

State police are still looking for a black sport bike they said fled down I-95 north after the shooting. 

Anyone with information is asked to contact them.