A man was rushed to hospital after being stabbed at Royal Holloway University in Surrey.
Police described the incident in the early hours of the morning as “very unusual".
Officers said they were called to a disorder at the university in Egham at about 4.30am on Thursday morning.
It is understood the victim and attacker are known to each other but the victim is not thought to be a university student.
Surrey Police said he was rushed to hospital after being stabbed but is not in a life-threatening condition.
Following the stabbing, there was a “proportionate police and security presence” across the campus to reassure students.
Neighbourhood Commander Nick Pinkerton said: "I want to reassure students, staff and the public that this was a very unusual incident and my officers are working hard to secure CCTV and other evidence, with support from Royal Holloway, to find and arrest the individuals responsible.
“If you saw or heard anything that you think could help our investigation, or if you have footage or photos from the altercation outside the library and shop area, please contact police urgently – either by calling 101, or speaking to an officer in person.
“I am aware that the students will be heading home for Christmas shortly, and I would like to speak to any students who can help our investigation before they leave."
Anyone with information is asked to call 101 quoting reference PR/45180132338.
