The alleged victims were walking along Glendale Plaza in the 4300 block of Dale Boulevard just after 9 p.m. – after trick-or-treating--when a man with a gun forced them into some nearby woods behind the shopping center, according to police.
The suspect allegedly forced the girls to lie on the ground and allegedly assaulted them.
A third girl --who was also present -- was not assaulted, according to investigators.
Police said the suspect fled the scene. The teens were treated at a nearby hospital.
Anyone with information about the case is asked to call Prince William County Crime Solvers at 703-670-3700.