A major fire raged for the third consecutive day at the Tuapse oil refinery on the Black Sea following a drone attack by Ukrainian forces, Russian authorities reported Wednesday. Air quality in the city has significantly worsened, attributed to the black coating of pollutants released by the blaze.

The Krasnodar region’s command center in Russia announced that efforts to contain the large-scale fire involve 276 firefighters and 77 vehicles. Byproducts from the fire have dispersed toxic substances like benzene and xylene beyond permissible limits, prompting public health warnings.

Authorities stated that normality will resume once the fire is under control. Russian officials noted increased Ukrainian assaults on Russia’s energy facilities, while the U.S. focuses on Middle Eastern conflict mediation. Infrastructure damages from recent attacks compound the ongoing regional hostilities.

(With inputs from agencies.)