Portuguese Prime Minister Antonio Costa said Thursday that the country will close schools primarily due to a marked increase in the highly transmissible UK variant of the coronavirus.

“Last week, data showed that the British strain had a low prevalence. This week, we’ve seen very significant growth,” he said at a news conference.

Portugal is suffering from one of the world’s worst COVID-19 infection rates. An additional 13,544 cases were detected Thursday – the second-highest surge on record.

But daily deaths reached an unprecedented high. Health officials reported 221 more lives lost from a population of a little more than 10 million.

The country entered full lockdown last Friday but schools remained open. Lockdown rules were further tightened Wednesday.

Still, experts convinced the government to take even more drastic measures Thursday, particularly due to surging infections caused by the UK variant.

Health Minister Marta Temido told Portuguese broadcaster RTP late Wednesday that the variant is responsible for around 20% of the cases sequenced in Portugal – up significantly from one week ago.

She warned the strain could make up 60% of all infections before the end of the month.

Schools will close Monday for at least 15 days, after which the measure will be re-evaluated based on the epidemiological situation.

In-person classes will not be substituted for online learning, and instead will be made up at later dates.

Schools will remain open for children under 12-years-old whose parents are essential workers.

"There isn't enough money in the world to pay for the harm that this measure inflicts on childhood development by interrupting the learning process," said Costa./aa