COPENHAGEN: Denmark said Tuesday it was toughening coronavirus restrictions and urged people to avoid social contacts, hoping to protect its health system from a coronavirus variant that first emerged in Britain.

On top of a partial lockdown in place since mid-December, Copenhagen will bar gatherings of more than five people -- down from 10 previously -- and ask people to remain two metres (six feet) apart, rather than one metre.

The new measures will take effect from Wednesday.

"Stay at home as much as you can, don't meet people outside your household, those close to you," Prime Minister Mette Frederiksen said at a press conference.

"Everyone should be thinking twice before stepping out of their door," national police chief Thorkild Fogde added.

Coming on top of existing measures like mass working from home and the closure of schools, bars, restaurants and most shops, the government hopes to lift the new steps by January 17.

But Frederiksen warned that they could be prolonged if case numbers do not fall, or even buttressed with a curfew "as a very last resort".

British authorities believe the new coronavirus strain is far more infectious than the regular Covid-19, and Denmark has already found it in 86 people.

So far Denmark has suffered 1,420 deaths and almost 173,000 coronavirus cases among its 5.8 million people.

A vaccination programme began on December 27 and so far 51,512 people have received a first injection.