State Schools Superintendent Karen B. Salmon called on school systems in suburban Maryland to begin bringing back at least some of their students for in-person instruction right away as learning losses accumulate.

Only a handful of the state’s 24 school systems have not brought students back to campus in some form. But the holdouts include the state’s two largest districts, in Montgomery and Prince George’s counties, which together educate nearly 300,000 students.

Students should return “right now,” she said in an interview. “The metrics are good, and I don’t say that with a cavalier attitude. We want to do this safely, we want to do it gradually, and we’ve had schools all around the state that show what can be done.”

Salmon’s remarks follow a “call to action” she issued Monday at a meeting of the Maryland State Board of Education. She cited research showing low infection rates in schools and cited the toll on students’ mental health and academics.

State board members spoke out one by one in favor of her effort, voting to formally support it.

Salmon said in the interview she is not urging that schools throw their doors open to crowds of children, only that steps be taken toward hybrid learning, which combines part-time in-person instruction with online learning.

“The metrics are good across the state for in-person instruction in some way in every county,” she said.

Montgomery County’s school board is slated to meet Nov. 6 and again Nov. 10 to discuss whether it might reopen for some level of school-based learning in coming weeks or months and what the plan will be for the school year’s second semester, which begins Feb. 1.

The school system also has developed a “health metrics grid” to show the health markers it is monitoring for a phased-in return to in-person instruction, a spokeswoman said.

“We will continue to thoughtfully plan and collaborate with the Board of Education, [school system] staff and the community on our reopening efforts, while keeping safety at the forefront of all we do,” said spokeswoman Gboyinde Onijala.

Prince George’s County said the county’s coronavirus case numbers are high and continue to rise, and that since March the school system has had cases in almost half of its school buildings.

“I also want our students back in our classrooms as soon as we can safely and responsibly do so,” said Monica Goldson, chief executive of the school system, in a statement. “We are listening to the voices of parents, educators, school leaders, and our community in planning the return of in-person instruction.”

Salmon’s comments drew mixed reactions in the two counties.

Patricia O’Neill, a school board member in Montgomery, said she would support a plan to bring small groups of students back into classrooms, particularly those in special-education and career programs, as well as English language learners and kindergartners.

“I don’t believe we can wait until the pandemic is gone,” she said. “I do believe we need to bring some children back to the building.”

She added: “We have to follow all of the necessary health protocols, but online learning is not working for some kids.”

County Executive Marc Elrich (D) started a weekly coronavirus briefing Wednesday by highlighting increases in cases, a trend that he said “is not an anomaly.” Asked about Salmon’s remarks, he took issue with the state’s view of health metrics.

“How they think this is safe is just beyond me,” he said.

State data showed Montgomery’s new daily cases per 100,000 residents at 11.94, higher than any point since June, and Prince George’s is greater, at 13.86. State education guidance says in-person instruction is possible in limited form when data show 5 to 15 new cases per 100,000 population.

County officials pointed to a recent announcement about the closure of schools in Dorchester County, on the Eastern Shore, because cases were on the rise.

Dorchester was the first school system in the state to retreat from its plan to phase in a return of students to campus. Officials said they would remain closed at least two weeks while they monitor data on coronavirus infections.

Salmon said the decision was evidence of health metrics driving the school system’s decisions and leading it to close as needed.

“We are in a world now where covid’s here,” she said. “We’re probably going to have the ebbs and flows of dealing with this pandemic. And they did the right thing with their metrics.”

She pointed out that the closure was related to spread in the community, not the schools. “They’ll be back open as soon as they feel it’s safe,” she said.