Police: Motorcycle-driving gunman sought in shooting that prompted closure of I-95

Police are searching for a motorcycle-driving gunman who they say opened fire on a minivan Monday afternoon along one of the busiest thoroughfares in Philadelphia.

The Pennsylvania State Police say the incident happened just before 1:30 p.m. on I-95 near the Columbus Boulevard exit ramps. 

A 911 caller reportedly told police that the driver of a "sportbike-type motorcycle" fired several rounds into his vehicle then fled down the highway at high speeds. 

The shooting and subsequent investigation caused the entire northbound side of I-95 to be closed for a little over an hour as officers canvased the ground for spent shells. 

A gold minivan with bullet holes peppered along the passenger's side was stopped on the Columbus Boulevard exit ramp. 

The highway reopened to motorists in time for the evening rush. Police have not said what prompted the shooting.