The St. Louis area is bringing back a mask mandate for all as the number of Covid-19 cases in Missouri continue to rise amid a more-transmissible variant, officials said.

Both the city and county of St. Louis will require masks to be worn by the vaccinated and unvaccinated alike in indoor public places starting Monday, the mayor's office said.

It is at least the second large county in the U.S. to return to a blanket mask requirement as the delta variant drives increased cases all over the country.