Northamptonshire Police were called twice in one night to reports of assaults near the University of Northampton.
On Tuesday, February 6 a man was assaulted in Kingsthorpe. Officers attended the scene near the bus stops at the university's Park Campus on Boughton Green Road, at about 10.30pm.
However, no trace of a victim could be found despite a large search of the area.
There was a further report of disorder near the halls of residence at about 11.45pm but the people involved had left the area upon officers’ arrival.
A short time later a man was taken to hospital with a minor leg injury which is believed to have taken place during one of the incidents at the university.
Detectives are investigating both incidents and are appealing for anyone who may have witnessed them, or have any information about them to make contact.
DS Simon Manwaring from Northampton CID, said: “We initially received a report of someone being assaulted near to the bus stop at Park Campus where a bus had stopped to collect passengers.
"We want to speak to anyone who may have been on that bus and saw what happened, or indeed witnessed anyone acting suspiciously in the area.
“We would also like to hear from anyone who may have witnessed the second incident, which we believe was witnessed by a large number of people. We would also like to speak to anyone who may have filmed the disorder.”
Officers are working with the University of Northampton as they continue their enquiries into what happened.
Witnesses or anyone with information about the incident can call police on 101 or independent charity Crimestoppers anonymously on 0800 555 111.