Among the affected UK universities, Northumbria University in Northeastern England confirmed 770 cases among students, making it one of Britain's largest single-site coronavirus outbreaks, the Guardian newspaper said, adding that the outbreak there has taken the total number of cases among students to more than 2,000 across 65 universities.

Meanwhile, the BBC reported around 56 universities across Britain have had at least one confirmed case, bringing the total number to approximately 2,500 positive cases.

There have been more than 200 cases at the University of Sheffield and 177 University of Liverpool staff and students have tested positive, according to a PA Media (a multimedia news agency operating in Britain and Ireland) survey which contacted 140 institutions.

The universities of Edinburgh and Edinburgh Napier reported more than 300 confirmed cases among their students, while the University of Glasgow had more than 170 and the University of Aberdeen said it had 99 cases.

Manchester University announced 221 cases among students and staff, while at the nearby Manchester Metropolitan University more than 1,500 students were ordered into isolation.

More than a third of Britain's population is now under heightened restrictions, according to the BBC.

"I've got to tell you in all candour it's going to continue to be bumpy through to Christmas, it may even be bumpy beyond," the prime minister said in an interview with the BBC's Andrew Marr Show program on Sunday.

"This could be a very tough winter for all of us -- we've got to face that fact," Johnson said.

To bring life back to normal, countries, such as Britain, China, Russia and the United States, are racing against time to develop coronavirus vaccines.

The British government's Chief Scientific Adviser Patrick Vallance has said that it is possible that some vaccine could be available in small amounts later this year, but it is more likely that a vaccine will be available early next year, although that is not guaranteed.