Three students and a female lecturer are in hospital after an 18-year-old man allegedly went on an attack with a baseball bat inside a classroom at the Australian National University (ANU) in Canberra on Friday.

ACT Policing said that shortly after 9am, an 18-year-old male student allegedly stood up from his seat with a baseball bat and approached the lecturer at the front of the class.

Three other students in the class – two female and one male – bravely ran towards her and attempted to restrain the student until at least 12 ANU security personnel arrived.

Police said the male student assaulted four people during the incident, one male and three females, including the lecturer.

The ACT Ambulance Service attended and treated the students and lecturer for sustained non-life threatening defensive injuries including broken bones and transferred them to the Canberra Hospital.

Police took the man, who is not known to police or intelligence agencies, into custody and said there was no known ongoing threat to public safety.

”Other students in the class have intervened and have attempted to restrain the student with the baseball bat,” acting deputy chief police officer Ben Cartwright told reporters on Friday.

There were no religious slogans or outbursts in foreign languages during the rampage. Several students in the class were Asian but the background of the lecturer is unknown.

“He put up a fight, obviously, when he had the baseball bat but once it was taken off him the students were able to restrain him and campus security were able to restrain him until police arrived,” Detective Cartwright said.

“Incredible bravery on their behalf,” Detective Cartwright said.

“I believe one of the students has actually taken the baseball bat from the student with it and run away with it, and then returned later and given it to police.”

“What we do know is that around 9:15am a student entered an ANU classroom and assaulted four other students,” Marnie Hughes-Warrington, the ANU’s deputy vice-chancellor said on Friday morning, shortly after the incident.

ANU statement on assault on campus this morning. There is no ongoing threat to public safety on campus. pic.twitter.com/PTURulrzI6

— ANU Media (@ANUmedia) August 25, 2017

“It would have been [confronting] for anyone who witnessed it.

“I don’t have the details, but the most important thing is to make sure anyone who was near the incident are being looked after, and that is the case.”

Student Alexander Vuong said a number of friends saw the incident as at least 12 ANU security staff rushed to the campus classroom.

One fellow student told Mr Vuong a man wearing a hoodie attacked a few other students with a baseball bat.

“Apparently he attacked some students first and then the lecturer,” Mr Vuong said.

Professor Hughes-Warrington said the event was “shocking for everyone” considering Canberra was a caring community.

She said she did not know the extent of students’ injuries nor the circumstances surrounding the incident.

ANU students received an email from the university alerting them of the incident and assuring them that the perpetrator was removed from campus and detained by police.

Police were yet to determine a motive for the attack.

— with AAP/ABC