A fire erupted at a major Russian oil refinery in the southwestern Volgograd region overnight after a drone attack blamed on Ukraine, the regional governor said Saturday.
Ukraine has launched drone attacks on Russia for months following Moscow's almost two-year offensive.
"Last night, the air defence and electronic jamming repelled an attack by drones in the Volgograd region's Kalachyovsky and Zakanalye districts," governor Andrei Bocharov said on Telegram.
"A fire started at the Volgograd refinery after one of the downed drones fell," he said, adding that the fire service had already brought the blaze under control by the start of the morning.
No one was hurt, Bocharov said.
Industry giant Lukoil, which operates the refinery, says on its website it is "the biggest producer of oil products in the federal South district" which covers eight regions of southwest Russia.
The plant is located south of the city of Volgograd.
Local media V1 published photos it said showed an overnight explosion during the attack.
Local resident told V1 they heard two explosions.
The Russian army said air defence electronic jamming had brought down or intercepted four drones in the region of Belgorod which borders Ukraine, two in Volgograd and one more in the Rostov-on-Don area.
Meanwhile, Ukraine's air force on Saturday said it downed nine out of 14 drones launched by Russia over southern and central regions overnight.
Kyiv said most of the drones were directed at energy facilities in the central Dnipropetrovsk region, where thousands have been without power since Russian strikes on Friday.
The outages have mainly affected the main city of Krivyi Rig -- the home town of President Volodymyr Zelensky.
"Ukraine destroyed nine enemy drones within the Dnipropetrovsk, Odesa, Mykolaiv and Zhytomyr regions," the air force said, adding that most of the Iranian-made Shahed drones were directed at "energy infrastructure facilities" in the Dnipropetrovsk region.
Regional head Sergey Lysak said 15,000 people were without electricity in the city after the drone strikes.
He said fires caused by the strikes affected "two boiler houses" in the city and said "some families were left without water supply".
He reported "no deaths or injuries" in the strikes but damage to two private houses.
The head of Kryvyi Rig, Oleksandr Vilkul, said energy companies will "introduce schedules of emergency shutdowns" in the city.
He said the city's high-speed tram will stop running and that a part of some hospitals will switch to energy generators.
Ukraine's energy ministry said it was working to restore critical infrastructure.
Russia has targeted Ukraine's energy infrastructure throughout its almost two-year offensive, leaving thousands of people without heat during an intense campaign last year.