MINNEAPOLIS — Minnesota health leaders warned Thursday that the fourth wave of the COVID-19 pandemic is putting heavy strain on hospitals and health care workers statewide as the coronavirus burns through the unvaccinated population.

They also said transmission in schools and among children is a particular concern, with pediatric intensive care unit beds in short supply, underscoring that the disease is not just a threat to older people.

The Minnesota Department of Health on Thursday reported 2,674 new cases and 32 additional deaths to raise the state’s totals to 732,001 known cases and 8,275 deaths. Health Commissioner Jan Malcolm said at a briefing for reporters that the state is now seeing more than 3,000 cases per week in children under 12, who aren’t yet approved for vaccinations.

“This represents a new and troubling high mark for the entire pandemic, and highlights the important point that COVID isn’t just a concern for older adults with underlying medical conditions,” Malcolm said. “This disease can and does impact young and healthy people, including children.”

Thursday’s numbers included 514 new cases among students and staff in K-12 schools, with 996 schools reporting cases, including 158 with five or more cases. The teachers union Education Minnesota reported the 11th death of a school staffer since the start of the pandemic. Minnesota hospitals were treating 881 patients for COVID-19, with 234 in intensive care, and 21 children were hospitalized with the disease.

Current hospitalization and ICU use levels are now above those of the surge last spring, Malcolm said, with some hospitals at or near capacity, and pediatric capacity at crisis point. That’s due partly to COVID-19 but also to high numbers of patients with trauma and other serious conditions.

“This is really an issue of health care worker capacity,” the commissioner said, adding that Minnesota has fewer health care workers now than it did last year “due to the extreme stress and burnout that they have faced for over 18 months.”

Dr. Kevin Croston, CEO at North Memorial Health, said both his hospitals have full ICUs and medical-surgical units. All of the coronavirus-positive patients in their ICUs were unvaccinated, he said, while 75% in the medical-surgical units who have tested positive have not been immunized.

“The staff are exhausted and they’re working harder than they ever have,” Croston said.

Rachelle Schultz, president and CEO of Winona Health, said her staffers are “working to the highest levels and the best of their abilities, but we could use more people and they’re not out there for us to get.”

Dr. Marc Gorelick, president and CEO of Children’s Minnesota, the state’s largest pediatric care provider, said the bump in COVID-19 isn’t the main reason his hospitals are nearly full, but it could put them over the top. He said the waivers of normal staffing and capacity rules that Gov. Tim Walz proposed Tuesday would help to reduce the stress on caregivers.

“They’re tired, they’re anxious, and they’re worried about their patients and their ability to provide the exceptional care those kids deserve,” Gorelick said.

The health system leaders and Malcolm put in a fresh plug for vaccination — calling it “our most powerful protection measure” to reduce the pressure on the health care system and health care workers — and for taking other standard steps to prevent transmission such as masking. She said 73.7% of Minnesotans 16 and up have received at least one dose.

State officials have been talking up the need for people to get their seasonal flu shots, too. Kris Ehresmann, the department’s infectious disease director, said it’s “just fine” for people to get their coronavirus and influenza vaccinations at the same time or close together, and there’s no need to space them out.