CHESTER, Pa. (WPVI) -- Police are investigating after two children were shot in the crossfire in Chester, Pennsylvania.It happened just after 7:30 p.m. Friday on the 600 block of Central Avenue.Police say an 11-year-old girl and a 13-year-old boy were wounded while playing in the area.The boy was shot in the stomach.He is undergoing surgery at Children's Hospital of Philadelphia in stable condition.The girl is also being treated at Children's Hospital of Philadelphia for less serious injuries.No arrests have been made.