The United Kingdom has seen its highest daily total of new coronavirus cases since late May, officials said.
There have been 2,988 cases confirmed in the past 24 hours, according to Health Secretary Matt Hancock, who noted that this figure was over 1,000 more than the prior day's tally of new cases.
The previous high figure was on May 22.
"The rise in the number of cases that we've seen today is concerning," Hancock said on Sunday. "The cases are predominantly among younger people but of course, younger people could pass on the disease to their grandparents and we do not want to see that."
In-person learning for children returned to the U.K. last week and universities and colleges are expected to resume classes in the coming weeks.
On Friday, the Department of Health and Social care announced that pools, gyms and sports facilities would be allowed to open across the country on Tuesday.
The U.K. currently has over 349,000 confirmed cases of COVID-19 and more than 41,000 deaths since the start of the pandemic.
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ABC News' Mike Trew contributed to this report.