A Ukrainian drone attack has caused a fire at a military facility in southern Russia.

The attack comes as Kyiv continues its offensive in the Kursk region where it has taken territory and prisoners, and struck key infrastructure including bridges, airfields and oil depots.

Andrei Bocharov, governor of the Volgograd region, said on Thursday that a “defence ministry facility” was on fire after being attacked by drones in the area of Marinovka, in a sign that Ukraine is not letting up on its attacks. He did not specify what was damaged.

Ukraine attacked Russia overnight with 28 drones, Russia’s Ministry of Defence said. Thirteen were shot down over the Volgograd region, seven over the Rostov region, four over the Belgorod region, two over the Voronezh region, and one each over the Bryansk and Kursk regions, the ministry said.

Russian Telegram channels said drones attempted to attack a military air base near Marinovka in the village of Oktyabrsky. Videos shared on Russian social media showed an explosion in the night sky, reportedly near the base. Marinovka is about 185 miles east of the Ukrainian border and about the same distance west from the border with Kazakhstan.

Ukraine did not acknowledge the attacks but it comes as Kyiv continues a ground offensive in Russia’s Kursk region that has rattled the Kremlin. The daring operation is the largest attack on Russia since the Second World War and could involve as many as 10,000 Ukrainian troops backed by armour and artillery, military analysts say.

This satellite photo from Planet Labs PBC shows a fire at an oil depot earlier hit by a drone attack near Proletarsk, Russia, on Monday
This satellite photo from Planet Labs PBC shows a fire at an oil depot earlier hit by a drone attack near Proletarsk, Russia, on Monday (Planet Labs PBC via AP)

The Baza Telegram channel, which is close to Russian law enforcement, said one drone was taken down several miles from the airfield and that wreckage from another fell on a trailer near the air base, causing it to catch fire.

Data from Nasa fire satellites, which monitor Earth for forest blazes, showed fires breaking out around the air base’s apron, where fighter jets have previously been seen parked.

Another fire burned on Thursday in Russia’s Rostov region, where firefighters struggled for the fifth day to put out a fire at an oil depot in the town of Proletarsk caused by a Ukrainian drone attack on Sunday.

Russian state television channels have largely avoided covering the attack. Russian Orthodox priests visited Proletarsk to pray for injured firefighters.

Independent Russian Telegram channels said another powerful explosion was heard on Wednesday evening and shared videos of a fireball burning in the night sky. State news agency Tass said 47 people were injured while putting out the blaze, but firefighters succeeded in stopping fires in six fuel tanks.

Satellite photos from Planet Labs PBC analysed on Thursday by The Associated Press showed the fire at the oil depot still intensely burning as of Wednesday. Storage tanks at the facility appeared engulfed in flames. Visible flames could be seen in the images, with a thick black smoke cloud drifting west over the city of Proletarsk.

This satellite photo from Planet Labs PBC shows a fire at an oil depot earlier hit by a Ukrainian drone attack near Proletarsk
This satellite photo from Planet Labs PBC shows a fire at an oil depot earlier hit by a Ukrainian drone attack near Proletarsk (Planet Labs PBC via AP)

In Russia’s Kursk region where Ukraine is still trying to push forward, the Kursk acting governor Alexei Smirnov said that authorities began putting up concrete shelters at bus stops and other locations around the city on Thursday to protect from shelling.

He said similar work will be done in Zheleznogorsk and Kurchatov, where the Kursk nuclear power plant is located.