LONDON (Reuters) -At least one patient has died in the United Kingdom after contracting the Omicron variant of the coronavirus, Prime Minister Boris Johnson said on Monday.

       "Sadly at least one patient has now been confirmed to have died with Omicron," Johnson told reporters.

       "So I think the idea that this is somehow a milder version of the virus - I think that's something we need to set on one side - and just recognise the sheer pace at which it accelerates through the population."

       Since the first Omicron cases were detected on Nov. 27 in the United Kingdom, Johnson has imposed tougher restrictions, and on Sunday he urged people to get booster shots to prevent the health service from being overwhelmed.

       Health Secretary Sajid Javid said the Omicron coronavirus variant was spreading at a "phenomenal rate" and now accounted for about 40% of infections in London.

       (Reporting by Guy Faulconbridge and Michael Holden; Editing by Angus MacSwan)