As many as 20 people were stabbed in an attack at Franklin Regional High School in Murrysville, Pa. Wednesday morning, according to media reports.
The Philadelphia Inquirer reports that four people were airlifted from the school, which is outside of Pittsburgh, in serious condition from the stabbing attack. A male student, identified in several media reports as Alex Hribal, 16, is in custody in conjunction with the attack.
The New York Times reported that the student went from classroom to classroom stabbing people. Information as to what may have prompted the attack has not been released. In that report, the Times quoted an official who said most of the injuries were to the extremities.
It is unclear whether those injuries are life threatening. CNN quoted a source who said some students are in critical condition. However, the Pittsburgh Post Gazette quoted an official who said none of the injuries were life threatening.
Three of the victims have undergone or are in the process of surgery for their injuries, according to the Times.
The attack happened shortly after 7 a.m., as students were arriving to school, according to several media reports. A witness told the Pittsburgh Post Gazette that the suspect was tackled by the school's assistant principal.
The FBI has been summoned to the crime scene, NBC News reported.
The school district updated its website with the following announcement:
"A critical incident has occurred at the high school. All elementary schools are cancelled, the middle school and high school students are secure. Additional information will be released as soon as possible. Please keep our campus clear of traffic."
Franklin Regional High School is located Westmoreland County, about 20 miles east of Pittsburgh.