CHICAGO (CBS) — More than three dozen immigrant children at a Heartland Alliance shelter for unaccompanied minors have tested positive for COVID-19.

As CBS 2’s Mike Puccinelli reported, it may be the largest cluster of migrant children with the novel coronavirus.

READ MORE: Two Chicago Police Officers Wounded By Accidental Friendly Fire While Confronting Suspect In Lyons, Police Say

Heartland Alliance operates three shelters for unaccompanied immigrant children in Chicago, and on Tuesday confirmed at least 37 children at one shelter have confirmed cases of coronavirus. Mailee Garcia, a spokeswoman for the group, said 28 of those children were asymptomatic when they were tested.

“Our doctors and nurses have been very closely monitoring the health of our participants and ensuring that employees are monitoring their health status as well,” Heartland Alliance said in a statement. “The prognosis for all of the children in our care is very good, and we are continuing to focus on our participants’ health and well-being.”

Heartland Alliance has a total of 69 children in its care at three shelters in Chicago, and Garcia said tests are being performed for all of the children.

“We are operating under the assumption that we will see additional positive diagnoses as we receive results from the other tests that have been administered, and the steps we are taking to ensure the health and safety of our participants and staff are based on that assumption,” Garcia wrote in an email.

ProPublica first reported on Monday that at least 19 minors and two staff members at the Heartland Alliance shelter in Chicago’s South Side had tested positive for coronavirus. Garcia said Tuesday there has not been an increase in cases among staff.

READ MORE: Man Shot, Killed After Argument At Bus Stop In Logan Square; Shooter Kills Second Man Nearby During Carjacking

“Our hearts go out to these children,” said Joe Boland, who has worked in shelters for the Catholic Extension of Chicago all around the country. “We know that this is a moment where they are incredibly fearful for their lives and for their futures.”

Heartland Alliance officials did not want to go on camera, but told CBS 2 all the infected children have been moved to an isolated environment in Bronzeville.

Boland understands the need for isolation, but worries that it will make a difficult situation even tougher for the children.

“We know that the levels of stress and anxiety are so high for them, and so to be experiencing even more change or more disruption to their live just adds, you know, more salt to the wound that’s already there,” Boland said.

Heartland Alliance said it has “implemented robust policies and procedures” to respond to the coronavirus outbreak, including moving children to an isolated environment if they show any signs of illness, enhancing social distancing measures to limit contact among children and between children and staff, requiring staff to wear personal protective equipment when they interact with children, screening employees before each shift, rotating staff to minimize the number of people on site, and performing weekly deep cleanings of its facilities.

The group also is contacting any employees who have worked on floors where children tested positive in the past week, and asked them to stay home with pay for two weeks. Heartland Alliance also has contracted additional nurses to work on every shift.

MORE NEWS: Chicago Weather: Cool Down In Effect

The Heartland Alliance would not provide any numbers when it comes to sick staffers.