Police were searching for a gunman who shot and injured an officer during a foot chase early Friday in North Philadelphia.

Officer Kevin Gorman, 33, a three-year member of the force, was treated for a shoulder wound at Temple University Hospital and released about 21/2 hours after the shooting, police said.

Police said Friday night that they were looking for Nasuil Martinez, 20, of the 2800 block of Lee Street. Police said he should be considered armed and dangerous. Police asked that anyone with information on Martinez contact the Homicide Unit at 215-686-3334 or -3335, or call 911.

Police said Gorman and his partner stopped a speeding silver Mercury Marquis with four men inside about 2:30 a.m. at Westmoreland and Hope Streets. Three of the men stayed in the car, but one bolted out through a back door, prompting Gorman to give chase, police said.

As Gorman climbed a fence on the 3300 block of North Howard Street, two shots rang out, said Police Commissioner Charles H. Ramsey. One hit the officer in a shoulder, and the gunman escaped.

Police took the three other men into custody and were questioning them. Philadelphia Lt. Raymond Evers, a police spokesman, said the gunman had a .45-caliber pistol.