It happened around 2:30 p.m. on the 700 block of East Hilton Street in Kensington, NBC reported.
Seven people were injured by the shooting. Three adults were taken to Temple University Hospital in the back of police cruisers. Two were in critical condition, one was in stable condition. An 11-year-old girl, 3-year-old girl, and 10-year-old boy were among the injured.
A shotgun was found at the scene. The shooter fled on foot.
Police do not yet know what prompted the shooting.
On Saturday, 10 people were injured during a shotgun shooting at a block party in West Philadelphia, three were children. Two suspects are still being sought.