MURRYSVILLE, Pa. -- A Pittsburgh-area high school is to resume classes one week after a student stabbed 21 others and a security guard, leaving four students still hospitalized.

Wednesday's normal schedule at Franklin Regional High School in Murrysville follows two days of activities meant to reassure students, parents and staff. Teachers participated in an in-service day following a grief counselling session Monday, and the school hosted an open house of sorts Tuesday so students and parents could tour the facility and speak with teachers and counsellors if they wished.

The suspect, 16-year-old Alex Hribal, remains in a juvenile detention centre though he's charged as an adult with attempted homicide and aggravated assault.

Hribal's attorney acknowledges the boy took two kitchen knives from home and randomly attacked his victims before classes began April 9.