MALDEN, Mass. (AP) — Students and employees in Massachusetts public schools will be required to wear face coverings indoors until at least the end of February, state Education Commissioner Jeffrey Riley announced Monday.

The mask requirement extension comes as new confirmed cases of the coronavirus driven by the omicron variant surge among students and staff at the state’s schools, causing staffing shortages at some. Nearly 39,000 students and more than 12,000 faculty and staff tested positive in the week ending Jan. 5, according to the latest data available.

“The mask requirement remains an important measure to keep students, teachers and staff in school safely at this time. The Department of Elementary and Secondary Education, in consultation with medical experts and state health officials, will continue to evaluate public health data,” the agency said in a statement.

The department will continue to give local school committees the option of lifting indoor mask requirements if at least 80% of all students and staff in a school building are vaccinated.

Riley, with approval from the Board of Elementary and Secondary Education, instituted the requirement in August, and has extended it a number of times. It applies to K through 12th grade students in all public schools, as well as faculty, staff, and visitors. Masks remain a requirement on school buses.

There are exemptions for people, who for medical or behavioral reasons, cannot wear a mask. Masks are also required for indoor athletic events.