Mass testing began on Wednesday at Kantor King Solomon High School in Redbridge. 

It is part of the government’s plan to offer testing to schools in districts with the highest Covid-19 infection rates. 

Pupils were able to get tests at a mobile unit stationed outside the school. 

Redbridge has one of the highest rates in the capital, with 477 positive tests per 100,000 people recorded last week, compared to the national English average of 159. 

London went into tier 3, the highest level of restrictions, on Wednesday. 

In the UK, Covid-19 infection rates are the highest among secondary school-age children, according to the Office of National Statistics.