KITCHENER -- Region of Waterloo Public Health officials have identified a "large cluster" of COVID-19 cases, including a variant of concern, linked to multiple social gatherings earlier this month.

In a Thursday release, regional officials said the gatherings occurred between March 4 and 7 at three private residences.

An investigation into the gatherings showed they were indoors with close contact for prolonged periods of time. Officials said people weren't maintaining physical distancing or wearing face coverings.

In the release, the region said one of the initial cases related to the gatherings has screened positive for a variant of concern. The specific variant hasn't been identified yet. They say the variant case and nature of the exposures resulted in high transmission rates.

There are 23 confirmed cases linked to the events, along with one probable case. Nineteen people have been identified as high-risk contacts.

“Waterloo Region remains in a precarious position and we are not immune to rapid acceleration of cases seen in other communities across Ontario,” Medical Officer of Health Dr. Hsiu-Li Wang said in the release. “This cluster of cases illustrates that it is essential that all residents continue to limit their mobility, limit their close contacts, and avoid social gatherings to slow the spread of COVID-19 in our community.”

Officials with the region said Dr. Wang will discuss the cases at the COVID-19 update on Friday morning.

"Within this cluster public health has identified a subset of individuals who have connections to both Wilfrid Laurier University and University of Waterloo, including on-campus exposures," a release from the region said in part. "Subsequently, our investigation has determined that on-campus transmission has occurred at the University of Waterloo and an outbreak has been declared for that setting with a total of two cases identified at this time."

The University of Waterloo sent out a tweet on Thursday saying there is an outbreak in Claudette Millar Hall associated with the cluster. Officials said public health will reach out to high-risk contacts and anyone with symptoms should get a COVID-19 test.

"This cluster is a reminder that we cannot let our guard down. Whether you're an employee or a student living on or off campus – please continue to avoid gathering with people you don’t live with," a tweet from UW said. "It's up to everyone to keep each other safe as we share the space on our campus."

This is the third outbreak at Claudette Millar Hall. There were previous outbreaks in November and December of 2020.

“It is disappointing to learn that some students have been putting themselves, their friends and families at risk by attending off-campus gatherings,” said Ivan Joseph, vice-president of student affairs at WLU, in a notice on the university's website. “This is unacceptable behavior that puts the health of friends, roommates, family, and the broader community at risk.”

“Where we have found that students have violated provincial laws and put the health and safety of others at risk, there will be consequences under Laurier’s Non-Academic Student Code of Conduct."

The notice said there have been eight COVID-19 cases confirmed in WLU students in the last 14 days. Six of those students live in residence buildings.

Officials said the students who have tested positive are in isolation and they don't believe there's been any spread in residence buildings at this time.

Health officials said residents should only be in close contact with people in their households.

Infectious disease specialist Dr. Gerald Evans said the B.1.1.7 variant is 50 per cent more transmissible than the original SARS-CoV-2 virus.

"It has a better affinity for attaching to cells in humans and we know that the period of transmission is actually longer in people who have the variant than it is for the original SARS-CoV-2," he said. "When the variant gets involved in a scenario where there's some transmission, it increases the risk for that to go further."

Evans said the driver of these transmissions is often younger adults in their 20s and 30s.

"When you think about a university residence for example, or young people gathering together, they are often the ones that often times will propagate transmission," he said.

Shayne Turner with Waterloo's municipal enforcement services said they just learned about the cases on Thursday afternoon.

"It's unfortunate that this outbreak occurred," he said. "If we had been aware of it going on at the time, we certainly would have attended and dealt with it appropriately. Any action now, after people have already tested positive, will not make the situation any better."

He said it will likely be difficult to gather sufficient evidence and facts to lay charges.

"Instead, we hope this serves as a cautionary tale about why it’s so important that everyone follow provincial regulations when it comes to gatherings," Turner said. "This pandemic is far from over, people need to make good decisions and not let their guard down and we hope for a speedy recovery for those that have caught COVID-19."

With reporting by CTV News Kitchener's Natalie van Rooy