Counter Terror Police investigating after attack at Sydney University

A 14-year-old boy has been arrested after a stabbing at the University of Sydney.

A 22-year-old man was treated by paramedics at the scene and taken to hospital in a serious, but stable condition.

Officers established a crime scene, and shortly afterwards arrested a teenager.

In a statement, New South Wales Police said it was not believed the pair were known to each other and there is not ongoing risk to the public.

According to local media, Counterterrorism police are now investigating the attack, though the motive is not yet known and it has not been declared terrorism.

It has been reported that the teenager was known to police and other government agencies.

ABC News reported that NSW Police Assistant Commissioner Mark Walton from the Counter Terrorism and Special Tactics Command said the suspect was dressed in camouflage in "Defence Force uniform" - though he has no known links to the military or cadets.

There is also no link with a recent terror attack in Sydney where a 16-year-old stabbed a bishop.

Assistant Commissioner Walton warned that parents should be aware of the risk of radicalisation online. He said: "I would, however, like to indicate that here in NSW, nationally and internationally, there are concerns about youth being radicalised in the online environment," he said.

"They are embracing violent extremist ideologies and moving towards violence."

In an email to students, the university's vice-chancellor Mark Scott said he was shocked and saddened: "A NSW Police operation is currently underway on our campus and ... as a precautionary measure, several buildings have been placed on secure mode.

"The safety and wellbeing of our community is our number one priority.

"We will continue working with police as their investigation continues and we will provide more details to our community today."