Estonia will go into a one-month lockdown in a bid to tackle the rapid spread of the British coronavirus variant, Prime Minister Kaja Kallas announced Monday night.

Schooling will be almost completely switched to remote learning and restaurants, cafes and retailers will have to close, with exceptions for shops selling essentials.

Indoor sport will also be prohibited under the rules, which come into force on Thursday.

"The Covid-19 situation in Estonia is extremely critical. This must be dealt with quickly. We have decided to shut down the country as far as possible," Kallas said in a televised address.

"This is all in the name of reducing contacts and breaking the infection chain."

The new restrictions are linked to the quick spread of the British coronavirus strain. According to Kallas, the variant has recently been found in 98 per cent of all analysed samples.

The country of 1.9 million people has one of the highest infection rates in Europe at the moment, according to the European Centre for Disease Prevention and Control (ECDC).

Since February 23, more than 1,000 new cases have been registered every day.

In response to the increase in infections, the government in Tallinn had already tightened up restrictions that had long been more relaxed than those of its neighbours Lithuania and Latvia.

Estonia has recorded more than 76,000 cases of coronavirus since the pandemic began, and 667 related deaths.

The British variant of the coronavirus is considered more contagious than the original form identified. Estonian media last week cited a recent study showing that the variant made up about 13% of the country's coronavirus infections.

Kallas had earlier warned that a lockdown could be coming, saying she had received information that the strain was spreading more in Estonia than previously thought.

"We still have to learn to live with this virus so that we can continue our daily lives as safely as possible. Therefore, extensive lockdowns are necessary," she wrote on Facebook.

Kallas had entered quarantine on Friday as a precautionary measure after being in contact with someone infected with the coronavirus.