NSW police investigating the stabbing of a 14-year-old student by another teen at a western Sydney high school say it may have been a targeted attack.

NSW Police Commissioner Mick Fuller said the attack appeared to be targeted, and the families of both boys were speaking to police.

He said the accused 14-year-old assailant was not yet in custody.

Police say the 14-year-old boy was stabbed in the back and arm by another 14-year-old boy at Arthur Phillip High School in Parramatta about 8.30am on Monday.

He was taken to Westmead Children’s Hospital in a stable condition, a NSW Ambulance spokesman said.

NSW Police said in a statement that local officers had established a crime scene and were investigating the incident.

Four ambulance crews were sent to the school and a strong police presence remained late into Monday morning. No arrests had yet been made.

“Our paramedics did an exceptional job in stabilising and providing treatment for the teenager who had suffered some pretty serious injuries,” NSW Ambulance inspector Joe Ibrahim said in a statement.

“It’s absolutely horrific when we respond to jobs like these, especially when it involves someone so young. It’s every parent’s worst nightmare.”

Lessons have resumed at the school but a police presence remains in place.

–with AAP