Police arrest teenager after student attacked at University of Sydney ...

Counterterrorism police are investigating after a student was allegedly stabbed in the neck by a 14-year-old boy on the grounds of the University of Sydney on Tuesday morning.

Paramedics were called about 8:35am after reports of a stabbing near Parramatta Road in Camperdown where they found a mansuffering from a single stab wound.

The 22-year-old was treated at the scene and taken to nearby Royal Prince Alfred Hospital in a serious but stable condition.

NSW Police Assistant Commissioner Mark Walton from the Counter Terrorism and Special Tactics Command said a motive or ideology for the attack had not been determined.

"That is an element of determining whether something is an act of terrorism," he said.

He said the injured student was stabbed in the neck with a kitchen knife and that the suspect was dressed in camouflage in "Defence Force uniform". 

The boy has no known links to the military or the cadets. 

Officers established a crime scene after the stabbing and were told the teenager had boarded a bus on Parramatta Road.

A short time later officers arrested the 14-year-old, who is from Sydney's inner west, near Royal Prince Alfred Hospital.

He was treated for cuts to the hand and is "currently undergoing a mental health assessment".

The boy was known to police and other government agencies. 

Police do not believe the teenager and the man he allegedly stabbed knew each other.

"This young person's activity is unknown, but I would say that it's likely to be categorised as mixed and unclear ideology," Assistant Commissioner Walton said. 

"It's certainly not a religiously-related ideology." 

Acting Assistant Commissioner Craig Palmer said the Australian Federal Police was "fully committed" to supporting the investigation.

"We're in here to ensure that all the circumstances that led up to this incident are understood clearly, and that we're committed to … protecting the community, making sure that no stone is left unturned."

Parents warned to be on alert

Assistant Commissioner Walton said parents needed to be aware of the growing risk of radicalisation which children were exposed to online, particularly on social media.

"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."

He urged parents to be aware and take action if they fear their child is consuming radicalised content. 

"Reach out to authorities if they are worried about the consumption of extremist ideologies," he said. 

"There are multi-agency support programs to assist families to respond to youth and adults who have shown an interest in violent extremism."

University responds to attack

The university's vice-chancellor Mark Scott this morning said he was "shocked and saddened" over the incident in an email sent to students.

"A NSW Police operation is currently underway on our campus and ... as a precautionary measure, several buildings have been placed on secure mode," he said.

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

A spokesperson for the university said earlier today that increased security and police presence would be considered as a precautionary measure.

Police said there was no ongoing risk to the community.

Federal Home Affairs and Cyber Security Minister Clare O'Neil confirmed she had been briefed on the stabbing.

"I've been briefed on the stabbing incident in Sydney by relevant agencies who are continually engaging with state law enforcement," she said.

"My thanks to our law enforcement, intelligence and security agencies for the vital work they do."