Air quality in Tuapse has deteriorated sharply after a major fire ignited at the city’s marine terminal three days ago by a Ukrainian drone strike, the Krasnodar Krai operational headquarters said.

Combustion byproducts entered the atmosphere and fell with rain over the city on April 22, leaving a black residue on surfaces, the headquarters warned residents. Benzene, xylene, and soot concentrations in some neighborhoods were two to three times above permissible levels as of the evening of April 21, it said, citing Rospotrebnadzor data.

Residents of several neighborhoods were advised to limit time outdoors, keep windows closed, mop floors more frequently, and wear masks outside when necessary. They were also urged to switch from contact lenses to glasses, rinse their nose, eyes, and throat, and refrain from smoking.

The headquarters said conditions would return to normal once the fire was extinguished.

The oil terminal at the port of Tuapse was attacked by Ukrainian drones in the early hours of April 20. Ukraine’s General Staff said the target was the Tuapse oil refinery, which forms a single industrial complex with the marine terminal. A major fire broke out after the strike and has been burning for three days, prompting locals to describe what they have been experiencing as “oil rain.” Residents complained that authorities had provided almost no information and had not canceled school classes, the independent Russian investigative outlet Agentstvo reported. Instead, on April 22, the Krasnodar Krai prosecutor’s office announced that its staff had taken part in a city beautification effort. A published photo showed prosecutors standing beside a flower bed against a backdrop of black smoke. The photo was later deleted.