As a result of the Center for Disease Control’s updated mask guidance, some Arizona cities will once again require mask usage in all municipal buildings regardless of vaccination status.

ABC 15’s Josh Frigerio reported Wednesday on Tucson Mayor Regina Romero’s tweeted statement earlier in the day reinstating mask requirements in city buildings.

Peoria will reportedly follow suit Thursday, and Tempe will readopt the policy starting Friday. Phoenix is set to begin requiring mask usage in city buildings on Aug. 2.

The updated guidance comes primarily as a result of the rapid spread of the Delta variant, also called B.1.617.2, of the coronavirus. The new CDC guidelines, confirmed Tuesday, state that masks should be worn indoors in areas where “substantial or high” community spread exists.

In Arizona, all counties except Cochise and Yuma (considered “moderate”) are considered in the high to substantial spread category.

Private businesses have the right to set their own mask requirements if no city or state policy exists.

Meanwhile, State Superintendent Kathy Hoffman tweeted a statement on Tuesday that urged Arizona Gov. Doug Ducey to give schools autonomy to set their own safety protocols for a return to safe in-person learning.

In an ABC 15 story posted Thursday, Nick Ciletti reported that COVID-19 cases in school-aged children are rising dramatically, while data analyst Garret Archer reports that COVID-19 cases among the 0-20 age group have risen 30 percent since mid-July.

“Any growth in COVID-19 is concerning. The biggest concern with the 0-20 age group is less about the severity and more about them being a vector point for getting other people sick,” Archer said.

“So if they have people at home who are unable to get vaccinated or chose not to get vaccinated, those people of a certain age group where COVID-19 may be more severe to them, they are more at risk when these numbers go up.”