A stabbing rampage occurred at a school near Pittsburgh this morning. 

Fox News Radio reports that one student at the Franklin Regional school in  Murrysville, Pennsylvania, east of Pittsburgh went room to room, stabbing students.

No one has died in the incident which occurred just after 7 a.m. Wednesday.  

Twenty students were injured. Four of them were airlifted to hospitals. 

But no students have life-threatening injuries.  

One alleged stabber is in police custody.