Twenty people were injured when a student at a Pittsburgh-area high school went on a stabbing rampage early on Wednesday, with four victims flown to area hospitals, officials said.
The suspected attacker, a student at the school, was in police custody, Dan Stevens, deputy emergency management coordinator for the Westmoreland County, told reporters.
The attacks took place in several classrooms and hallways as the school day commenced at Franklin Regional High School in Murrysville, 20 miles (32 km) east of Pittsburgh, county emergency management officials said. The first 911 call was received at 7:13 a.m. EDT (1113 GMT), they said.
Seven teenagers and one adult were admitted at the Forbes Regional Hospital, the hospital's director of trauma, Chris Kauffman, told reporters.
"These are significant injuries," Kauffman said, noting that two patients were undergoing surgery and a third was headed to the operating room.
"It's important that parents realize the scene is contained, the students that are here are safe," Stevens told reporters.
It wasn't clear how many students were stabbed and how many injured while scrambling to get away from the attacker.