Washington DC – States blocking schools from imposing mask mandates on teachers and students could face federal civil rights investigations, Education Secretary Miguel Cardona said on Sunday.

He cast mask-wearing as part of students’ rights, though he voiced reluctance to withhold federal funds from states that block them.

"We are prepared to launch investigations with our Office for Civil Rights to ensure that all students have access to this fundamental right of education. And it’s sad that we’re talking about this now," Cardona told NBC’s Meet the Press.

"We’re going to use our Office for Civil Rights to investigate any claims that come forward to make sure that students’ rights are kept," he added.

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The governors of Florida and Texas have tried to prevent school districts from imposing mask mandates – a cause that has gained urgency as Covid-19 numbers spike nationwide.

But last week, Texas dropped its ban amid legal challenges.

Florida is pushing ahead with its prohibition on mask mandates, with the state government threatening to withhold salary funding for school board members in districts that are requiring masks.

Cardona said Florida can’t block federal funding to the districts in question, adding that he doesn’t want to use federal money to punish states banning mask mandates, either.

"I spoke to the superintendents of those two communities and I let them know that we have their back. And yes, they can draw down on the funds that were promised to them so they can safely reopen schools," he said.

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On the consequences of possible civil rights investigations, Cardona said: "At the end of the day, when we talk about withholding funds, those who suffer are the students. So we want to make sure that we’re communicating with them."

The comments came as the US has been seeing its second-biggest surge in Covid-19 cases since the start of the pandemic; only this past winter’s surge was worse.