A major incident has been declared in London as the COVID crisis threatens to overwhelm hospitals in the U.K. capital city.

London Mayor Sadiq Khan said the situation is now critical amid rising numbers of patients being admitted with COVID-19. Khan made the emergency declaration to fast-track national help for the National Health Service, which he said was on the verge of running out of beds.

“I have declared a major incident in London because the threat this virus poses to our city is at crisis point,” he tweeted. “One in 30 Londoners now has COVID-19. If we do not take immediate action now, our NHS could be overwhelmed and more people will die.”

The mayor said the virus was “out of control” in the capital and ordered Londoners to stick to the rules and not mix indoors over the weekend. The number of patients in London hospitals grew by 27 percent from 5,524 to 7,034 between December 30 and January 6, the latest data shows.

Over the last three days alone the NHS has announced 477 deaths in London hospitals following a positive test for COVID-19.

Ambulances at the Royal London Hospital in London, England, as the number of COVID hospital patients rises
Dan Kitwood/Getty

This is a developing story and will be updated as new information becomes available.