PHILADELPHIA (CBS) – Police are investigating a murder in North Philadelphia.

The incident occurred just after 2 a.m. on the 5900 block of Opal Street in the Logan section of the city.

Detectives say an officer heard shots fired and discovered a 20-year-old man lying on the ground.

The victim was taken to Einstein Medical Center where he was pronounced dead.

Police say a gun and four shell casing were recovered near the victim.

No arrests have been made.

Police are still investigating.