Ukraine launched a drone attack on a Russian metal plant in a border region on Wednesday, causing a fire at a fuel tank, the local governor said.
Kyiv meanwhile announced it had intercepted dozens of Russian drones as both sides launched a wave of overnight aerial attacks in an attempt to hit targets deep behind the front lines.
"Today another attack on the Kursk region was carried out by Ukraine," Kursk governor Roman Starovoyt said in a video message posted on his Telegram channel on Wednesday morning.
"A drone attacked a fuel and lubricants warehouse in Zheleznogorsk. There are fires in the area right now," he added.
He said later a second drone had hit the depot at the Mikhailovsky Mining and Processing Plant in the city of Zheleznogorsk, some 90 kilometres (55 miles) from the border with Ukraine.
Videos posted on Russian social media showed thick grey smoke billowing as a fire raged inside a cylindrical fuel storage tank.
There was no immediate comment from Kyiv.
Ukrainian forces have launched a wave of drone attacks at Russian energy facilities in recent months, trying to target the country's vital energy and gas sector that it says Russia uses to fuel its invasion.
Ukraine also said that Russia fired 42 Iran-designed attack drones and five missiles at its territory overnight in a barrage that injured at least seven people.
"As a result of combat operations, 38 Shaheds were shot down," the air force said in a statement, referring to the unmanned aerial vehicles, adding that the drones were launched from Russian border regions and the annexed Crimean peninsula.
Kyiv has appealed to its Western allies to help bolster its air defences to fend off systematic Russian aerial attacks on key infrastructure throughout the two-year invasion.
Ukraine's prosecutor general said seven people including a 10-year-old boy were injured during the overnight attacks in the eastern Sumy region.
One of the drones fired at the Sumy region had targeted a hospital where 400 patients were housed, Governor Volodymyr Artiukh said.
In the northeastern Kharkiv region, a school and kindergarten building were damaged, though there were no casualties, the regional prosecutor's office said.
Officials in the southern Odesa region said a recreational facility, a gas pipeline and residential buildings were damaged by debris from the downed drones and some residents in the Khmelnytsky region were left without electricity after the attack.
Regional officials in Russia said Ukraine had also fired artillery and drones at the Belgorod border region. Governor Vyacheslav Gladkov said there was some minor damage, but no casualties.
Russia's defence ministry said it had downed Ukrainian drones over the Belgorod and Voronezh regions.
Russian President Vladimir Putin will meet the head of the International Atomic Energy Agency, Rafael Grossi, in Sochi later Wednesday to discuss the situation at the Zaporizhzhia nuclear power plant.
The facility, Europe's largest nuclear energy site, was seized by Russian troops in the first days of the war.
The Kremlin also said Wednesday it does not recognise International Criminal Court arrest warrants issued Tuesday for two top Russian officers over alleged war crimes conducted in the invasion of Ukraine.
Russia is not a member of The Hague-based court.
