LONDON, United Kingdom -- Ireland said on Friday it will tighten COVID-19 curbs over Christmas, including closing nightclubs and reintroducing social distancing in some settings, as infections rise and fears over the Omicron variant grow.

The new restrictions, to run from next Tuesday until January 9, include social distancing in all bars, restaurants and hotels, with hospitality outlets required to operate table service only.

As well as nightclubs closing, entertainment, cultural, community and sporting events must be kept at 50 percent capacity and guests will have to wear masks.

Meanwhile visits to private homes should be kept to a maximum of three other households at any one time.

Announcing the new measures, Irish Prime Minister Micheal Martin insisted the country was not "going back to the days of lockdowns".

"It's about adjusting the guidelines to meet the threat we face today and protecting the progress achieved to date," he said.

"If Omicron takes hold and if it is more transmissible, the potential for a very serious crisis is obvious." Ireland has so far identified just a single case of the new variant inside the country, but Martin noted daily Covid-19 case numbers "are still very high".

"Every time we have faced a new challenge we have pulled together as a nation and done what was needed," he said.

"I'm asking us all to do that again." Prior to Omicron's emergence, as case rates and hospitalisations climbed, the government had asked people to work from home again in mid-November and expanded its vaccine booster and certification schemes.

That is despite Ireland having one of the highest vaccination rates in the world, with around 90 percent of over-12s fully jabbed.

It only fully reopened on October 22, after 18 months of rolling lockdowns introduced to limit infections.

Officials recorded 5,419 new cases on Friday, up on previous weeks, while more than 5,700 people have died from the virus in the country of around five million.