A gasoline station caught fire early Wednesday near a vital bridge connecting Russia’s mainland to Crimea, according to a Russian official, only days after Moscow claimed Ukraine for an attack that set fire to an oil facility in Sevastopol.

In footage shared on Russian social media, flames and black smoke billowed over what seemed to be massive tanks painted with red “Flammable” warnings, though Reuters was unable to independently verify either the fire claims or the videos.

“The fire has been classified as the highest rank of difficulty,” Veniamin Kondratyev, the governor of the Krasnodar region lying across the Sea of Azov from Ukraine, said on the Telegram messaging app, adding that there were no casualties.

Kondratyev said the blaze broke out in the village of Volna. The hamlet is close to the Crimean bridge over the Kerch Strait, a major artery for Russian forces, as it links the mainland to the Crimean peninsula that was annexed in 2014 from Ukraine.

The incident came days after a drone strike set ablaze a Russian fuel storage facility in the Crimean port of Sevastopol on Saturday, in what Moscow called a Ukrainian attack.

Ukraine did not claim responsibility for the Sevastopol attack, in line with its standard practice during the conflict, which began in February 2022.

Over the weekend, however, Kyiv’s military said undermining Russia’s logistics formed part of preparations for a long-expected counteroffensive, aided by fresh deliveries of more powerful Western weapons.

Blasts derailed a train on Monday in Russia’s region of Bryansk bordering Ukraine, the second such incident in two days. Russian officials say pro-Ukrainian sabotage groups have made attacks there since the start of hostilities.

Russia has also stepped up attacks on Ukraine ahead of a counteroffensive expected by the latter, with nearly nightly waves of drones and missiles targeting Kyiv and other areas over the past week.

Early on Wednesday, authorities in the Ukrainian capital said they parried Moscow’s overnight attack as air defence systems destroyed all the drones launched.