Ukrainian President Volodymyr Zelensky said on Sunday that the military carried out drone strikes on two Russian refineries during the night.
He confirmed the strike on a facility in Slavyansk-na-Kubani in southern Russia, which Russian authorities had reported earlier.
"We also struck a refinery in the Yaroslavl region, which is about 700 kilometres from our border," he said on Telegram, though the information could not be verified.
Zelensky said Ukraine is planning more strikes on strategic Russian targets. "Each of our long-range strikes reduces the resources available to the Russian war machine and is a step towards peace," he said.
The refinery in Yaroslavl is said to be one of the largest in Russia. It has recently been repeatedly targeted by Ukrainian attacks, causing damage that required repairs.
The authorities in Yaroslavl have not yet confirmed a strike, although Governor Mikhail Yevraev had issued a drone alert. He also said roadblocks were set up near the oil refinery before later lifting the alert without providing details on any consequences. Images shared on social media do not indicate the extent of the damage.
Earlier, Krasnodar Governor Veniamin Kondratyev said a fire had broken out at a refinery in the southern Russian region following a Ukrainian drone attack.
One person was killed in the attack. Aside from the refinery in Slavyansk-na-Kubani, several houses, a power line and a gas pipeline were damaged, he said on Telegram.
It appeared to be a major fire, according to images and videos shared online. With a processing capacity of 4 to 5 million tons of oil per year, according to various sources, the facility is not particularly large.
However, as it is near Ukraine's Crimean Peninsula, annexed by Russia, Kiev has attacked and damaged the refinery several times.
Other Russian regions, including Ivanovo, north-east of Moscow, also reported drone attacks. The Russian military said it shot down 213 Ukrainian drones, suggesting this was another massive attack.
Ukraine takes lead in drone war
Russian President Vladimir Putin ordered the full-scale invasion of Ukraine in February 2022. Since then, the Russian military has destroyed Ukrainian cities, killed thousands of civilians and forced millions of people to flee their homes.
Kiev seeks to repel the invasion by attacking strategic Russian targets such as military and arms facilities or oil refineries in the Russian hinterland.
Ukraine has increasingly gained the upper hand in the drone war recently, causing a fuel shortage in Russia.
