London, Dec 11 (IANS): Mass Covid-19 testing will be rolled out in secondary schools in England's worst-hit boroughs of London, Essex and Kent, amid fears that teenagers are fuelling the latest surge of infections in the UK, Health Secretary Matt Hancock announced.

Secondary school children in seven boroughs with the highest infection rates will be given the chance to take a rapid lateral flow test, which gives results in half an hour, Xinhua news agency quoted Hancock as saying at Downing Street press briefing on Thursday night

It is hoped the mass testing strategy will help bring down the soaring number of infections in those areas and prevent the capital from being plunged into a Tier Three lockdown.

Addressing the briefing, the Health Secretary said by far the fastest rise in coronavirus infection rates was among 11-18 year-olds, therefore all children in this age group should get tested, irrespective of whether they had symptoms.

"We need to do everything to stop the spread in school-age children now," Hancock said, adding that more details would be set out on Friday.

The announcement of the mass testing came after Wales announced ON Thursday that it will move to online learning for all secondary school children in a "national effort to reduce the transmission of coronavirus".

Hancock said the government must take "targeted action" immediately as "we know from experience that a sharp rise in case in younger people can lead to a rise among more vulnerable age groups later".

London and Essex are currently in Tier Two -- the second-highest level, which means no household mixing is allowed anywhere indoors and the rule of six applies outdoors.

Kent is in Tier Three, the highest level.

The British capital has recorded an average infection rate of 191.8 cases per 100,000 people for the week between November 30 and December 6, the highest in England, according to data from Public Health England (PHE).

The UK's overall caseload and death toll have increased to 1,792,611 and 63,179, respectively.