The governor of the Russian republic reports on Telegram that the oil giant Gazprom's refinery Neftechim has been attacked by Ukrainian drones. A source within Ukraine's security service SBU confirms to The Kyiv Independent that the country was behind the attack.
In video clips verified by, among others, BBC, a huge, black cloud of smoke can be seen rising towards the sky.
The facility in the city of Salavat, which is located about 120 miles southeast of Moscow, was also attacked last week. Then, a massive explosion was reported after two drone strikes.
The Kyiv Independent describes the complex as "one of Russia's largest refinery and petrochemical facilities".