Ukraine’s military has said it struck an oil refinery in Russia’s Saratov region in an overnight drone attack, causing explosions and destruction, according to an army statement, as daily aerial exchanges intensify with diplomatic momentum to end the war in play.

Saratov’s governor said on Sunday that one person was killed and several residential apartments and an industrial facility were damaged, but did not mention the oil refinery being struck.

Ukraine’s military also said on Sunday that it had taken back a village in the Sumy region from the Russian army which has made significant recent gains there.