London, one of the busiest cities in the world, has become reminiscent of a scene from a science fiction movie as streets empty after Prime Minister Boris Johnson urges Britons to stay at home and self-isolate because of the coronavirus pandemic.

During a televised coronavirus update on Wednesday, Prime Minister Johnson would not rule out enforcing a shutdown of London, which is the worst affected region in the country, saying: “We’ve always said that we are going to do the right measures at the right time.”

“Actually I think a lot of people are taking a real heroic effort to comply with the advice we’ve given but as I’ve said tonight, and in the past few days, we keep everything under continuous review and we will not hesitate in bringing forward further and faster measures where we think that is necessary,” Johnson added.

Meanwhile, The Telegraph reports that sources speaking to the newspaper from the London mayor’s office expect a formal shut down within days. A source close to Mayor Sadiq Khan said: “We expect a shutdown of London, but nobody in central Government is saying when that will be or what form it will take.

“The Prime Minister is saying we need to go faster and further, and there is a spike of cases in London which is running ahead of the country — but what that actually means, the Mayor’s office doesn’t yet know because Downing Street hasn’t said.”

Even without a government-mandated lockdown, much of the major hubs of the capital already appear abandoned. Some of the English capital’s biggest tourist attractions such as the Queen’s official residence, Buckingham Palace, and Trafalgar Square are almost completely deserted.

On Monday, Prime Minister Boris Johnson advised Britons to undertake “social distancing” to prevent the spread of the China-origin COVID-19, telling them to “avoid pubs, clubs, theatres, and other such social venues”. As a result, many of London’s museums appear much as they do when closed, while the streets of the city’s theatre district are empty.

Prime Minister Johnson also asked Britons to work from home where possible, resulting in London’s transport system carrying a fraction of its average passenger load.

And even places of worship, including the neo-Byzantine Catholic Westminster Cathedral, are attracting few visitors.