Ryazan oil refinery, operated by the Rosneft oil company, has halted around half its refining capacity since August 2 following a Ukrainian drone attack last week, three industry sources said.

Ukrainian drone attacks sparked a massive fire at an oil depot in a rare attack on the Black Sea resort of Sochi.

Ukraine conducted a crippling drone strike on a Russian supply rail hub, sparking transport disruption, while Russia continued its civilian attacks, killing 7.