PHILADELPHIA (AP) — Philadelphia police say a boy charged with aggravated assault was expected to surrender Saturday in connection with a shooting that wounded two students at a high school gymnasium.

Police say another boy already in custody in Friday's shooting at the Delaware Valley Charter High School in north Philadelphia has not been charged yet.

Police aren't identifying either boy because of their age, but say they've been in contact with the second suspect's parents, which is why they expected him to turn himself in.

Police have said it appears two students were wounded when one of the suspects accidentally fired the gun.

Police say a girl was treated and released for a bicep wound. The same bullet then hit a 17-year-old male student who remained hospitalized in stable condition.