SOUTHWEST PHILADELPHIA (WPVI) -- Police are investigating a shooting that left four people wounded in Southwest Philadelphia.They say the victims showed up to several different hospitals Friday night.Someone opened fire around 9:25 p.m. at 55th Street and Springfield Avenue.Police arrived to find two males in front of Wanda's Bar suffering from gunshot wounds.Those victims were rushed to Penn Presbyterian Medical Center.A 63-year-old man suffered a gunshot wound to his head and chest. He is listed in critical condition.A second victim, a 28-year-old man, suffered a gunshot wound to his back. He is listed in serious condition.A third victim, a John Doe, was also taken to Penn with a gunshot wound to his arm and foot. He is listed in stable condition.A fourth victim, an 18-year-old male, was treated for a gunshot wound to his foot and then released.He told police he was outside the bar with two friends when he heard gunshots.He says he took off running, and felt he was shot in the foot.He then stopped an unknown person who drove him to the hospital.Officers described the four victims as the "walking wounded."Police are trying to determine if the victims were two factions shooting at each other.Investigators are also questioning the men who dropped the victims off at the hospitals.So far, no arrests have been made.