A shooter came out of the woods near the school and shot three students on Crane Avenue, local TV station KDKA quoted school officials as saying. After the shots were fired, the students ran back into the school for help.
None of the victims' injuries are believed to be life-threatening. One was shot in the leg and foot, and another was shot in the neck and shoulder. The last victim was grazed in the head by a bullet.
None of the injuries are life threatning, police said
The school said the shooting may have been related to an incident at the school in October, which prompted heightened security for about a week. Police are searching the nearby woods for at least one shooter. It is not known at this time if there is more than one shooter.
The three victims were being taken to UPMC Mercy Hospital and Allegheny General Hospital. At least one student was said to be in stable condition.
The school is located in Beechview and is part of the Pittsburgh Public Schools District. There are about 1,500 students in the school, making it the largest high school in the district.
After the shooting took place, police closed off Crane Avenue near the school, and nearby South Hills Middle School has also been placed on lockdown.