MURRYSVILLE, Pa. — A doctor says some victims of a multiple stabbing at a high school near Pittsburgh have suffered injuries classified as life-threatening, though all are expected to survive.

Dr. Chris Kaufman says two victims were in the operating room and one was awaiting surgery at Forbes Regional Medical Center, a few miles from Franklin Regional High School in Murrysville.

Officials say four students were believed to be the most seriously injured Wednesday morning by a fellow student who stabbed or slashed others, injuring as many as 20.