Greater numbers of American children are being swept up in a wave of coronavirus infections driven by the Delta variant, causing renewed anxiety for parents and a bitter political fight as schools prepare to reopen within weeks.

Much of the surge is concentrated in the southeastern state of Florida, where some school districts are defying an order by the Republican governor forbidding mask mandates, in the latest political twist in the health crisis.

“Parents are put into an impossible situation of having to choose between the health and life of their child and returning (to) school,” said a lawsuit against the governor's order filed by parents of children with disabilities.

The majority of children who catch the coronavirus will have a mild or asymptomatic disease, and until recently they had not been a major focal point of the pandemic.