British Prime Minister Boris Johnson talks with political commentator Andrew Marr during BBC’s Andrew Marr Show on Sunday in London. Photo: AFP

British Prime Minister Boris Johnson announced Monday evening a series of measures that aim to restrict social contact in the United Kingdom, so as to curb the spread of COVID-19.

Johnson made the announcement during a TV address to the nation. "From this evening I must give the British people a very simple instruction: you must stay at home," said the prime minister.

Starting from tonight, people in Britain will only be allowed to leave their homes for "very limited purposes," including shopping for basic necessities, for any medical need, for one form of exercise a day, and to travel to and from work when necessary, said Johnson.

Meanwhile, all shops selling non-essential goods, such as clothing and electronic stores, are ordered to close, and places like libraries, playgrounds, and outdoor gyms will also be closed.

All social events and even gatherings of more than two people in public, excluding people one lives with, are banned.

Police have powers to enforce the rules, including through fines and dispersing gatherings, according to Johnson.

The tougher new measures will be in place for at least three weeks from this evening, according to the government.

The announcement came after the prime minister warned Sunday that the government will have to go further if people do not follow its advice.

The government has been stepping up its measures in recent weeks. It was only on March 20 that the government announced that Cafes, bars, pubs and restaurants, etc. must close.

But during the weekend, large groups of people can still be seen in some parks and tourist hot spots, prompting concerns that many people might be ignoring the government's advice of avoiding social contact.

This is in addition to the fact that the growth of UK's COVID-19 cases is still substantial.

As of Monday morning, there had been 6,650 confirmed cases of COVID-19 in the UK, an increase of 967 in the past 24 hours, according to the latest figures released by the Department of Health and Social Care. A total of 335 COVID-19 patients had died, the figures showed.

"Without a huge national effort to halt the growth of this virus, there will come a moment when no health service in the world could possibly cope; because there won't be enough ventilators, enough intensive care beds, enough doctors and nurses," said Johnson.