Russian shelling of Ukraine killed four people on Saturday, officials said, as the two countries exchanged drone attacks, one of which burned a Russian oil depot.

Two people died in Ukraine’s partly occupied Kherson region, and two were wounded in the attack close to the regional capital, said Governor Oleksandr Prokudin. Two other people died Saturday afternoon and 16 were wounded in Ukraine’s northeastern Kharkiv region, according to Governor Oleh Syniehubov.

An oil depot in the Tsimlyansky district, deep inside Russia’s southwestern Rostov region, was set on fire in the early hours of Saturday following a Ukrainian drone attack — the latest long-range strike by Kyiv’s forces on a border region.

Ukraine has in recent months stepped up aerial assaults on Russian soil, targeting refineries and oil terminals in an effort to slow down the Kremlin’s war machine. Moscow’s army is pressing hard along the front line in eastern Ukraine, where a shortage of troops and ammunition in the third year of war has made defenders vulnerable.

Rostov Governor Vasily Golubev said the drone attack caused a fire spanning 200 square meters (2,100 square feet), but there were no casualties. Some five hours after he reported the fire on the Telegram messaging app, Golubev said it had been extinguished.

In addition to two drones being intercepted over the Rostov region, Russian air defense systems overnight destroyed two drones over the country’s western Kursk and Belgorod regions, the Russian Ministry of Defense said.

Ukraine’s air defenses, meanwhile, intercepted four of the five drones launched by Russia overnight, the Ukrainian air force said. The fifth drone left in the direction of Belarus, said air force commander Mykola Oleschuk.

Meanwhile, eight people were wounded in shelling in the town of Shebekino in Russia’s Belgorod region bordering Ukraine, Governor Vyacheslav Gladkov said Saturday.

Vadym Filashkin, the Ukrainian governor of the partly occupied eastern Donetsk region, said that Russian attacks on Friday had killed six people and wounded 22.

Also on Saturday, the Kremlin warned that the deployment of U.S. missiles in Germany could make European capitals targets for Russian missiles.

The U.S. and Germany announced Wednesday they would begin “episodic deployments” of long-range missiles to Germany in 2026, including Tomahawk, SM-6 and hypersonic missiles.

“We have enough capacity to contain these missiles, but the potential victims are the capitals of these countries,” Kremlin spokesperson Dmitry Peskov said, speaking on Russian state television.