Spain’s autonomous region of Catalonia has made face masks mandatory in public for all those aged over five after a surge in new cases of coronavirus.
Anyone caught without a mask – even when social distancing can be observed – faces a €100 ($113; £90) fine.
It comes amid an outbreak of the virus in Segrià, an agricultural area.
Officials already imposed a lockdown on 210,000 residents on Saturday, banning anyone from entering or leaving except for work.
While the national situation is largely under control, Spain has been hit hard by the virus. As of Wednesday the health ministry said the country had recorded 252,513 cases and 28,396 deaths.
Spain’s northwestern region of Galicia imposed a local lockdown around the coastal district of A Mariña following a fresh outbreak earlier this month.
And in June the region of Aragon, which borders Catalonia, re-imposed restrictions on several areas after an outbreak among fruit pickers in its Huesca province.