The NHL and the National Hockey League Players' Association have announced the suspension of all operations from Wednesday to Christmas Day amid an increase of positive COVID-19 tests.

The league and players' association announced in a joint statement Monday night that all NHL team facilities will be closed until Boxing Day,

The league's decision will result in five additional NHL games being postponed – all were scheduled to be played on Thursday. All four matches on Wednesday had already been postponed.

The league's holiday break was initially scheduled to begin Friday and end Sunday.

The NHL has been forced to scrub 49 games this season, with 44 announced since Dec. 13.

After the shutdown, practices can resume Sunday afternoon and games are scheduled to resume next Monday.

When team facilities reopen, all people travelling with the team will only be able to access the facility by showing a negative COVID-19 test result.

The two remaining games on the schedule before the new holiday break are on Tuesday when the Philadelphia Flyers host the Washington Capitals, and the Tampa Bay Lightning are in Vegas.

Prior to the league-wide shutdown, the Montreal Canadiens, Edmonton Oilers, Ottawa Senators and Columbus Blue Jackets were the latest teams sidelined by COVID-19. They joined the Toronto Maple Leafs, Boston Bruins, Colorado Avalanche, Detroit Red Wings, Florida Panthers and Nashville Predators.

The Calgary Flames, who have endured the largest outbreak across the league with 32 people impacted, had re-opened their facility to members of the organization that had remained negative throughout daily testing. But that facility will be closed again until Boxing Day.

Ottawa and the New York Islanders were previously shut down by the league because of COVID-19 outbreaks earlier in the fall.

The NHL and the NHL Players' Association previously said in a joint statement the plan was to avoid a full-league shutdown, instead choosing to continue halting team activities on a case-by-case basis.

Unlike last season, the league isn't providing a daily count of players in COVID-19 protocol, but the number currently stands at roughly 15 per cent.

The NHL issued a statement Monday when announcing the Canadiens and Blue Jackets would be shuttered that repeated a line that's been used over the last week. It indicated the decision was made "due to concern with the number of positive cases within the last several days as well as concern for continued COVID spread."

Columbus was supposed to visit Buffalo on Monday, but cancelled its morning skate while awaiting test results, some 24 hours after scrapping practice due to virus concerns. The Blue Jackets were also scheduled to host the Sabres on Thursday.

The Oilers then announced defencemen Darnell Nurse and William Lagesson have been added to protocol, joining five teammates and head coach Dave Tippett. Edmonton had already planned to close its facility through the Christmas break.

The league, which said Saturday it was immediately returning to tighter health and safety measures akin to last season's COVID-19 rules in hopes of curbing virus spread, also postponed two games set for Tuesday — Pittsburgh-New Jersey and Seattle-Arizona.

All but one NHL player — Detroit winger Tyler Bertuzzi — is vaccinated against the coronavirus.

The Canadiens, who added forward Mike Hoffman to protocol late Monday afternoon, said over the weekend they were closing their facility until Dec. 26 as a preventive measure. The government of Quebec then announced a single-day provincial record of 4,571 new COVID-19 infections.

Along with the six other Canadian-based clubs, Montreal had already seen its remaining games before the holidays postponed following the league's decision Sunday to temporarily pause cross-border travel through Thursday.

The NHL also said it would be announcing a decision later this week with the union on participation at the 2022 Beijing Olympics, but the string of COVID-19 postponements has almost certainly paved the way for the league to pull out of the Winter Games in China.

The Leafs announced Monday two members of their support staff have entered protocol. Toronto has seven players, including captain John Tavares and No. 1 goalie Jack Campbell, in isolation along with head coach Sheldon Keefe.

Canadian public-health officials have said COVID-19's latest mutation has the potential to spread more quickly than the Delta variant, which was already highly transmissible. It's also not currently known whether Omicron carries a higher or lower risk of severe illness or death.

When it comes to immunity, being fully vaccinated and then getting a booster shot is expected to reasonably protect against infection, and likely offers strong protection against severe illness. However, experts have said that must be combined with layers of public-health measures and individual precautions.

Canadiens winger Brendan Gallagher spoke with reporters Sunday — prior to the team being shut down — for the first time since he was sidelined by the coronavirus earlier this month.

The 29-year-old said he experienced some "pretty tough symptoms" the first couple of days.

"It got me hard … just laying there, fighting it," Gallagher told reporters in Brossard, Que. "But after two days I was good, and then it was eight days of me (quarantining) with my thoughts and a little bit of boredom in the house. I did some cleaning, played a lot of video games, watched a lot of movies, made a lot of phone calls, and checked in on the guys quite a bit.

"It took a while for me to get (COVID-19), but now that you went through it, you understand what everyone's been going through."

Gallagher added there's definitely been talk among players about a league-wide pause to the schedule.

"We're having those conversations, for sure," he said. "I understand the NHL's standpoint. We've got to get an 82-game season in — we have to.

"We knew we were going to have to deal with this, and this was a potential and a possibility."

--With files from Joshua Clipperton

This report by The Canadian Press was first published Dec. 20, 2021.