Ukraine struck the Yaroslavl oil refinery for the fourth time in a month, as drones also hit the Syzran facility in a widening campaign targeting Russia's refining capacity.

Ukraine's military reportedly struck the Nevinnomyssk Azot plant in Russia's southern Stavropol Krai overnight on May 20, Russian Telegram media channels reported.

Russia's Ryazan oil refinery has suspended operations following a Ukrainian drone attack last week. — Ukrinform.