LONDON: The British government said Thursday that it would begin offering coronavirus tests for children aged 11-18 in the worst-affected parts of London and southeast England to try to cut a rise in infections.

UK Health Secretary Matt Hancock said he was "particularly concerned" about a spike in cases in London, and parts of the counties of Kent and Essex that border the British capital.

He told a news conference that the data showed the biggest jump among children of secondary school age, which could have a knock-on effect in older people in the weeks to come.

"We need to take targeted action immediately," he told reporters.

Month-long coronavirus restrictions were eased across England earlier this month, but unlike during the three-month UK-wide lockdown in late March, schools remained open.

Mobile testing units will be sent to the affected areas to test children, whether or not they have symptoms of Covid-19.

"I urge everybody involved to get a test," said Hancock.

A further 516 deaths within 28 days of a positive test were recorded in Britain on Thursday, taking the overall toll to more than 63,000 from nearly 1.8 million cases.

Britain earlier this week became the first country to begin giving the Pfizer-BioNTech Covid-19 vaccine at 73 hospitals across the country.

The programme will be rolled out to doctors' surgeries next week and in care homes by Christmas.