Knife-wielding student wounds 22 in Pennsylvania school

A still image from video footage courtesy WPXI-TV shows stabbing suspect Alex Hribal dressed in a hospital gown after his arraignment with Sheriff's deputies in Export, Pennsylvania April 9, 2014. REUTERS/WPXI-TV

MURRYSVILLE, Pennsylvania (Reuters) - A 16-year-old student wielding two knives went on a stabbing rampage in the hallways of a Pittsburgh-area high school on Wednesday, wounding 22 people before he was tackled by an assistant principal, officials said.

The attacker moved furtively through the halls of Franklin Regional High School in Murrysville, stabbing his victims in the torso and slashing their arms and faces, students and officials said. Some of the injured taken to nearby hospitals were listed in critical condition.