According to Russian officials, a Ukrainian drone set fire to an oil refinery in southern Russia, and shelling targeted a Russian village near the border for the third time in a week, destroying houses and cars and wounding four people.

A day after Russia accused Ukraine of deploying drones to target buildings in Moscow, Ukrainian artillery blasted the Russian town of Shebekino, some 7 kilometers (4.5 miles) north of the border with Ukraine’s Kharkiv area, regional Governor Vyacheslav Gladkov stated on Telegram.

Two people were hospitalised and the shelling smashed windows and damaged roofs of an eight-storey apartment building, four homes, a school and other places, he said.

The governor of Russia’s southern Krasnodar region said a drone was the likely cause of a fire that broke out at the Afipsky oil refinery.

The fire was soon put out and there were no casualties, Governor Veniamin Kondratyev said on Telegram. The Afipsky refinery is not far from the Black Sea port of Novorossiisk, near another refinery that has been attacked several times this month.

There was no immediate information on who launched the drone but Moscow has accused Kyiv of increased attacks inside Russia in recent weeks, while Russia has repeatedly pounded Ukrainian cities with drones and missiles.

Reuters was not able to independently verify the reports.

The skies over Ukraine were relatively quiet on Tuesday night, with no major air raids reported. Russian drone attacks killed one person and wounded four in Kyiv on Tuesday, according to Ukrainian officials.

The attacks inside Russia come as Ukraine prepares a counter-offensive to drive Russian forces out of territory they have occupied since their full-scale invasion of Ukraine in February 2022.

Ukraine almost never publicly claims responsibility for attacks in Russia or on Russian-controlled territory in Ukraine.