The University of Manchester has said data has "likely been copied" during a cyberattack on its computer systems.
It is not yet clear what information has been accessed by the attackers, but staff and students have been advised to watch out for any suspicious emails.
The National Cyber Security Centre (NCSC) and National Crime Agency are among the authorities working with the university's own experts to resolve the incident.
A statement said: "We are working to understand what data have been accessed and will update you as more information becomes available."
The university has apologised to its community for the breach, which is being investigated.
"Our priority is to resolve this issue and provide information to those affected as soon as we are able to, and we are focusing all available resources," it added.
