PHILADELPHIA—Violence claimed the lives of four people in different parts of the city over a span of several hours, police said Sunday.

Shortly before midnight Saturday, officers responded to a report of a shooting in the Mantua section of west Philadelphia. They went to Presbyterian Hospital after learning that a 26-year-old man had been taken there by private vehicle, with wounds to his right arm and back, and he died at the hospital shortly after midnight.

Police said an officer heard gunshots at about 1:10 a.m. in west Philadelphia and saw a man running down the street. The man fell in front of the police vehicle, and he was taken to Presbyterian Hospital, where he was pronounced dead at 3:15 a.m.

Officers were called to a south Philadelphia bar at about 1:15 a.m. Sunday after a report of a stabbing. They found the 44-year-old man behind the bar in T-Barr's with chest wounds, and he was pronounced dead at the scene minutes later. Investigators told WPVI-TV that according to surveillance video, a man in a hoodie walked into the bar and demanded money, then stabbed the victim, stole cash from the register and fled.

Minutes later, police were called to a shooting at a block party in northwest Philadelphia that left one man dead and three others injured. Police told WPVI-TV that several men got into a shootout at the party in the East Falls neighborhood. Police say a 33-year-old man was shot in the head and died at the scene. A 19-year-old man was shot several times and is in critical condition. Two other men were in stable condition.