Students trying to escape a lockdown party at a residential hall after a fire alarm went off were trapped inside by a door fault, a university has said.
The University of Manchester (UoM) said a faulty mechanism stopped more than 80 people leaving Fallowfield's Unsworth Park at about 02:00 GMT on Saturday.
Firefighters had to use an axe and a sledgehammer to get the door open.
A UoM spokesman said safety checks were being carried out, but reminded students that parties were illegal.
He said the party was a "serious incident" where the presence of "more than 80 people in a flat led to a fire alarm being triggered".
"There was an issue with the door mechanism in the flat which led to the emergency services being called to assist," he said.
"Fortunately no-one was seriously injured."
He said the university was "looking into the issue with the door mechanism" and was checking "every similar door" at Unsworth Park.
He added that the university had "reissued safety messages to students advising them large gatherings are not just illegal, but are putting the health and safety of students at risk".
The latest figures showed Manchester, which will move into tier three when the national lockdown ends on Wednesday, had a Covid-19 infection rate of 206.2 cases per 100,000 people on 25 November, down from 302.8 per 100,000 seven days earlier.
Greater Manchester Police have been approached for comment.
There have been tensions between UoM and students during the pandemic.
Those living in halls were offered a 30% reduction on the semester's rent by the university on 25 November, having previously been offered a two-week rent reduction.