A playground sits empty last week at a Philadelphia public school temporarily closed to in-person learning.
CNN  — 

The spread of the highly transmissible Omicron coronavirus variant is forcing some US schools to halt in-person learning because of high case rates and teacher absences.

The vast majority of schools are operating as normal. But at least 2,141 schools were not offering in-person learning as of Thursday, according to data company Burbio, which aggregates data based on school calendars and other sources.

That’s an improvement from the more than 2,800 schools that were not open Tuesday for in-person learning. And districts in Los Angeles, Chicago and Atlanta moved forward with returns to classrooms this week.

Still, several large public school districts announced in just the past few days they were temporarily moving to remote learning. Here is a snapshot of some of the large districts that have done so:

Cincinnati: Cincinnati Public Schools have temporarily gone to remote learning because of staff shortages from “increased community spread of Covid-19,” the district said Monday. In-person learning could resume on Monday, January 24, if staffing levels are sufficient, the district said.

Indianapolis: Indianapolis Public Schools will have remote learning for middle and high schools Thursday and Friday, “based on the number of staff absences, including Covid-19 isolation and quarantines at the middle and high school levels,” the district announced Wednesday. The district said it plans to reopen those schools for in-person learning on Wednesday, January 19, following two days when students already had been scheduled to have no school.

Las Vegas area: Nevada’s Clark County School District – the fourth-largest in the US – said it is taking a “five-day pause” starting Friday to deal with its “extreme staffing shortages based on the high number of positive Covid-19 cases.” Students will not have school Friday or on January 18; Monday was already scheduled as a day off for Martin Luther King Jr. Day.

Minneapolis: Minneapolis Public Schools will temporarily move to online learning from Friday through Thursday, January 27, “in response to a significant reduction in staff available to work in person due to Covid-19,” the district said Wednesday. No school will be held January 28 because of teacher conferences, so in-person learning will resume January 31, after a weekend.

Oklahoma City: The entire district will hold online learning the rest of this week and plans to return in-person on Tuesday, after the Martin Luther King Jr. holiday. “Unfortunately, we continue to see a significant number of our teachers, instructional and support staff and students out across the district due to illness or other circumstances,” a message Wednesday from Superintendent Sean McDaniel reads. “Even after working to reassign staff at all levels across the district, we have determined that we can no longer adequately sustain a safe and meaningful learning environment for our students.”

Philadelphia: Nearly a third of the city’s 323 schools have shifted to remote learning because of a combination of the threshold level of positive cases of Covid-19 and a review of staffing data. “We will continue to make school-by-school decisions based on the most current staffing data, and ask that you prepare for the possibility of virtual learning at any time,” Superintendent Dr. William Hite said Tuesday.

Rochester, New York: Many of the schools there are open, but 21 are doing remote learning until Tuesday because of staff absences.

Santa Fe, New Mexico: Schools there will go virtual beginning January 18, with a return to in-person instruction planned for January 24 “if conditions improve,” according to the district. The shift is due to a spike in Covid-19 cases, Superintendent Larry Chavez said Tuesday. “SFPS ended last week with 361 cases involving students and staff, the largest ever in one week for our district, with many still being investigated,” Chavez said. “Cases could rise to near 600 this week, and we have seen increased spread in classrooms.”