Ukrainian drones have again hit oil infrastructure in the city of Perm in central Russia, more than 1,500km from the front line.
Ukraine's Security Service (SBU) said the target in Perm was an Lukoil-owned oil refinery - one of the largest in Russia.
Dramatic images shared on social media showed huge columns of black smoke and flames rising into the air, and a chemical emergency alert was issued for some parts of Perm. City authorities later claimed the alert was merely a test.
The attack on the Lukoil facility in Perm is the latest in a series of successful strikes launched by Ukraine on Russian oil infrastructure in response to Russia's continued aggression.
Moscow continues to target Ukrainian cities with aerial attacks on a regular basis and on Wednesday night killed at least three people and injured 79, including a child.
