The accident happened shortly after 4:00 p.m. along the 1300 block of East Hector Street.
Officials say two vehicles collided.
One child was flown to Children's Hospital of Philadelphia. A 12-year-old boy was transported to Mercy Suburban Hospital. The two other victims were taken to the Hospital of the University of Pennsylvania and Jefferson University Hospital, respectively.
All injuries are said to appear non-life-threatening.
Whitemarsh Police say the roadway has been shut down between North Lane and Barren Hill Road for an unspecified period of time.
