A university in Newcastle was hit by a cyber attack, which led to exams being cancelled and the clearing hotline being disrupted.
Northumbria University said there had been "operational disruptions across networks and IT systems" on Friday.
It said "immediate action" had been taken to mitigate the impact and it was working with external specialists who have launched an investigation.
The Information Commissioner's Office and police have been informed.
The university said in a statement: "The investigation is still at an early stage and we are currently assessing the scope of the incident."
Students were told in a letter that there would be no access to campus for the rest of the week, and the student portal and other online platforms used in day-to-day studies had been temporarily switched off as a precautionary measure.
Those with assessment deadlines would be granted an extension, and students were assured they "will not be disadvantaged as a result of lost time or system access".
Elsewhere in the city, Newcastle University has also reported a "number of operational issues" but it is not known at this stage whether the two incidents are linked.