The U.S. Education Department is investigating five states over their mask mandate bans.

 The Education Department has initiated investigations into five states whose prohibitions on universal mask mandates in schools may run afoul of civil rights laws protecting students with disabilities, federal officials announced Monday.

The department’s civil rights head wrote to state education leaders in Iowa, Oklahoma, South Carolina, Tennessee and Utah, notifying them that the department’s Office for Civil Rights would determine whether the prohibitions are restricting access for students who are protected under federal law from discrimination based on their disabilities, and are entitled to a free appropriate public education.

The investigations make good on the Biden administration’s promise to use the federal government’s muscle — including civil rights investigations and legal action — to intervene in states where governors and other policymakers have come out against mask mandates in public schools. The Centers for Disease Control and Prevention recommends that everyone in schools wear masks, regardless of vaccination status.

In letters to state leaders, the acting assistant secretary for civil rights said the department would explore whether the prohibitions “may be preventing schools from meeting their legal obligations not to discriminate based on disability and from providing an equal educational opportunity to students with disabilities who are at heightened risk of severe illness from Covid-19.”

The department said it has not opened investigations in Florida, Texas, Arkansas or Arizona because those states’ bans on universal indoor masking are not being enforced in schools because of litigation or other state action.

On Friday, a Florida court rejected an effort by Gov. Ron DeSantis, a Republican, and other state officials to prevent mask mandates in schools.

Sydnee Dickson, Utah’s superintendent of public instruction, said in a statement on Monday that while she appreciated the federal department’s efforts to protect children, she believed “they have unfairly defined Utah as a state where mask mandates cannot occur.”

She said that the state’s law left the decision up to local officials, and that several counties had implemented them. She noted that the C.D.C., in March, studied a Utah district as an example of how elementary schools had reopened without significant outbreaks.

Oklahoma and South Carolina education officials signaled that they opposed their states’ prohibitions on mask mandates.

Joy Hofmeister, Oklahoma’s superintendent of public instruction, said in a statement that the State Department of Education planned to cooperate with the investigation. Oklahoma’s law against mask mandates “is preventing schools from fulfilling their legal duty to protect and provide all students the opportunity to learn more safely in person,” she said.

In a statement, the South Carolina Department of Education said that the state superintendent “has repeatedly implored the legislature to reconsider” a recently passed proviso on mask mandates, which it said was being challenged in court.

The department said it “is particularly sensitive to the law’s effect on South Carolina’s most vulnerable students.”

Brian Symmes, the communications director for Gov. Henry McMaster of South Carolina, wrote in a statement that the federal investigation by the Education Department was “another attempt by the Biden administration to force a radical liberal agenda on states and people who disagree with them.”

He continued, “Under South Carolina law, anybody who wants to wear a mask — in a school setting or elsewhere — is free to do so, but the governor isn’t going to ignore a parent’s fundamental right to make health decisions for their children.”