By Brendan O’Brien

(Reuters) -Pennsylvania Governor Tom Wolf on Tuesday issued a mask mandate for all K-12 school and child care facilities to protect against the spread of COVID-19, three weeks after the Democrat said he would leave the decision to individual districts.

The order, which goes into effect Sept. 7, comes amid a surge in COVID-19 cases due to the highly-contagious Delta variant of the virus.

Since July, Pennsylvania’s COVID-19 case load has increased from less than 300 a day to more than 3,000 a day, according to the state’s health department.

“With case counts increasing, the situation has reached the point that we need to take this action to protect our children, teachers and staff. The science is clear,” the state’s acting Health Secretary Alison Beam said in a statement.

The decision comes as millions of public education students head back to schools across the United States. School districts, state education agencies and governors across the nation are grappling with masking and vaccination requirements.

In South Carolina, for example, the state’s supreme court heard arguments on Tuesday in two cases involving mask mandates in city of Columbia schools.

The order in Pennsylvania requires students, teachers and staff to wear masks in all public and private K-12 schools. The order also applies to child care providers and early learning programs. The order does not apply to school sports or outdoor activities.

In early August, Wolf said he intended to leave the decision to require masks in schools up to individual districts.

“Unfortunately, an aggressive nationwide campaign is spreading misinformation about mask-wearing and pressuring and intimidating school districts to reject mask policies that will keep kids safe and in school,” he said.

(Reporting by Brendan O’Brien in Chicago; Editing by Chris Reese and Bill Berkrot)