Four killed in Ukrainian drone strike on industrial zone in Russia's Volgograd

Four people were killed and two injured in a Ukrainian drone attack on an industrial zone in Russia's southern city of Volgograd, regional governor Andrei Bocharov said on Friday, the deadliest attack on the city so far.

Volgograd, known as Stalingrad during World War II, is home to a large oil refinery run by Lukoil and many other industrial facilities.

Unverified video posted on social media purported to show a large fire at the refinery, which has been attacked several times before, including last month, on May 29 and July 31, and residents took to social media to report loud explosions overnight.

There was no official confirmation that the refinery had been attacked and Lukoil did not reply to a request for comment.

Ukraine has sharply stepped up its attacks on Russian oil refineries since the end of October, when an energy ceasefire announced by US President Donald Trump failed to take hold.

Such attacks have temporarily reduced Russia's oil refining capacity by about 30 per cent, two industry sources said this week. According to Lukoil's website, the refinery has a processing capacity of approximately 14 million tonnes of crude oil per year, or 280,000 barrels per day, which accounts for about 5 per cent of total refining volume in Russia.