Ukrainian drone hit oil depot storage in southern Russia and fire has broken out over its large area.
Russian media say four oil tanks caught alight and the fire then spread over an area of 1,000 sq m (10,763sq ft).
Russian authorities in the Bryansk region say no-one was hurt.
The Bryansk governor said the drone was intercepted near the town of Klintsy and its explosives then fell on the oil depot, reports BBC.
The drone strike is the second on Russian oil facilities in two days.
An unprecedented attack targeted a major oil loading terminal in Russia's second city, St Petersburg, on Thursday.
Russian reports suggested that drone was shot down without causing damage but there were indications in Kyiv that the attack, so far from the Ukrainian border, marked a new phase in strategy.
"Yes, last night we hit the target. This thing crossed 1,250km (776 miles) last night," said Ukraine's Strategic Industries Minister Oleksandr Kamyshin on Thursday.
Russia's defence ministry said on Friday that its air defence systems had brought down a Ukrainian drone over Bryansk at 06:40 local time (03:40 GMT) and regional head Alexander Bogomaz said later that two further drones had been destroyed without damage.
As the fire raged for several hours at the Klintsy oil depot some 70km north of the Ukrainian border, black smoke was seen billowing over neighbouring railway tracks. More than 30 people were evacuated, the governor added.
There were also reports of a drone strike on a gunpowder factory near the city of Tambov, hundreds of kilometres north-east of the Ukrainian border.
A source at Ukraine's main intelligence directorate told media in Kyiv there would be further attacks on military targets inside Russia as most of its air defence and electronic warfare systems had been concentrated in occupied parts of Ukraine.
Bd-pratidin English/Lutful Hoque
