Police are looking for two men who opened fire with semiautomatic rifles on a South Philadelphia street early today, killing a man.

The shooting erupted on the 1200 block of South 21st Street in the Point Breeze section about 3:10 a.m., police said.

Witnesses told police two men armed with rifles ran out from Titan Street and then opened fire on a man standing with a group of people.

The victim, who was in his early 20s, fled, but was hit in the leg, chest and back.

He was taken in critical condition to the Hospital of University of Pennsylvania, but doctors could not save him and he died at 4:48 a.m., police said.

The crime scene was still littered with shell casings hours later.

Police have not disclosed a possible motive.

The slaying was one of two overnight in the city.

Earlier, officers on patrol before 10 p.m. Wednesday heard three gunshots and saw a crowd running from the 1600 block of West York Street in North Philadelphia, police said.

On the street they found Kareem Shaw, 19, a resident of the block, with a gunshot wound to the back.

Shaw was taken Temple University Hospital, where he died at 10:10 p.m., police said.

Despite the apparent number of possible witnesses, police said they have no motive or suspect in the shooting.