HALIFAX -- There are nine new cases of COVID-19 in New Brunswick -- the largest one-day increase in the province in more than two months.

All of the cases are in Zone 5, or the Campbellton region, Dr. Jennifer Russell, the province's chief medical officer of health, said at a news conference in Fredericton on Monday afternoon.

That brings the total number of active cases in New Brunswick to 24 -- and all are in Zone 5. The province completed 684 tests over the last 24 hours.

Among the new cases are two people in their 60s, four people in their 70s, one person in their 80s, and two people in their 90s.

Eight of the new cases are residents of Manoir de la Vallee, a nursing home in Atholville, N.B., where 14 residents and three staff have been diagnosed with the virus.

Five of those residents are in hospital in stable condition.

"We are doing everything we can to keep the residents safe," Dr. Russell said.

The other new case is a close contact of a previously confirmed case and public health officials are doing contact tracing.

Dr. Russell said that, given the 14-day incubation period of COVID-19, the new cases are expected and she expects more among the 300 people who began self-isolating because they were close contacts of previously confirmed cases.

"One of the things that we have learned about COVID-19 is its ability to rest quietly in the host for up to two weeks," Dr. Russell said.

Dr. Russell reminds people that, while the outbreak is in Zone 5 right now, it could spread outside of that zone to the rest of the province. She says, when you can't maintain physical distancing, you should wear a mask.

"It may be a week or more before we can say with certainty that the virus is not present in other regions of New Brunswick from this outbreak." Dr. Russell said. "It is so important that all New Brunswickers remain vigilant against the spread of COVID-19."

Premier Blaine Higgs called attention to a traveller who came into the province and didn't self-isolate for 14 days after returning from Quebec. They went to a business in Fredericton and this business followed protocol by shutting down so it could disinfect.

"This kind of behaviour is not acceptable and puts us all at risk," Higgs said. "We know that people will continue to get COVID-19 with self-isolation rules in place to help reduce the risk of spreading it."

On Sunday, 69 vehicles were denied entry at the border and the province's non-compliance line received 35 calls.

Every call is investigated, but Higgs said there is no way police and public health officials are going to catch everyone who breaks the rule. He reminded the scofflaws whose lives they are jeopardizing -- it's their parents or their grandparents.

"Let's not lose sight of the fact that the virus is here; COVID-19 is alive and well in New Brunwick," Higgs said. "The threat of COVID-19 to our province has not gone away, and we must all continue to take measures to keep ourselves and our loved ones safe. It will not be easy, but if each of us does our part, we can navigate our way through this outbreak."

There have been 146 confirmed cases in the province and 121 of those have recovered -- including the first person in the Campbellton cluster to recover. There has been one death; Daniel Ouellette, an 84-year-old resident at Manoir de la Vallee, died on Friday.

In other news, Vitalité Health Network says the Campbellton Regional Hospital's emergency department will completely reopen Tuesday at 8 a.m.

The ER will be open 24/7. Ambulatory care services and elective surgeries will be able to resume "gradually over the next few days."