Three students have been fined £10,000 each for holding a house party that up to 100 people attended.
The students from the University of East Anglia in Norwich were supposed to be self-isolating after showing symptoms of Covid-19.
Norfolk Police were called to the house in Bowthorpe Road, outside the university campus, in the early hours of Sunday.
The university said it fully supports the actions of the police.
One Bowthorpe Road resident, who did not want to be identified, told the BBC: “They are just irresponsible and don’t care about their neighbours.
“They are not protecting themselves or other people.”
- ‘Scandalous’ cost of Covid students’ food cut
- ‘He’s stuck in a room with Covid miles from home’
- University gives empty student rooms to NHS staff
Norfolk Police said a 19-year-old woman and two 20-year-old women had been issued with the fixed penalty notices.
In a statement, the force said at 01:10 BST on Sunday officers had found “up to 100 people attending a party at the address”. Under the coronavirus restrictions a maximum of six people are allowed to meet.