"The Ryazan oil refinery was attacked by a UAV," Pavel Malkov, governor of the Ryazan region that borders the Moscow region to its north, said on the Telegram messaging app on Wednesday.
"A fire broke out in result. According to preliminary information, there are injuries," he said, without elaborating.
More than 30 drones were destroyed in the air over the Voronezh region that borders Ukraine, Governor Alexander Gusev, said on Telegram, adding there was only minor damage.
Wednesday's attacks follow one of Ukraine's largest air operation insider Russia's territory on Tuesday, when Kyiv pounded targets in Russia with dozens of drones and rockets in an attack that inflicted serious damage on a major oil refinery.
Russia's President Vladimir Putin accused Kyiv of attempts to interfere with the upcoming presidential election through its attacks.
"The main goal, I have no doubt about it, is to - if not to disrupt the presidential elections in Russia - then at least somehow interfere with the normal process of expressing the will of citizens," Putin told Russia's RIA state news agency and Rossiya-1 state television in a wide-ranging interview.
Putin, who launched a full-scale invasion of Ukraine two years ago, is nearly certain to win the March 15-17 presidential vote.
In Voronezh, which also came under the attack on Tuesday, the "danger of a UAV attack still remains," Gusev wrote early Wednesday on Telegram.
A drone was also downed on its approach to an oil refinery in the Leningrad region, Alexander Drozdenko, the Leningrad region's governor, said on Telegram. There was no impact on the refinery's work.
In the Belgorod region, falling debris from downed drones damaged a gas supply line and cut off power to some villages.
Vyacheslav Gladkov, the governor of the Belgorod region, said on Telegram four Ukraine-launched drones were destroyed and some houses were damaged in the town of Gubkin.
He also said the town of Shebekino came under fire from Ukrainian forces, injuring one man and damaging a power line in the town and nearby villages.
Roman Starovoit, governor of the Kursk oblast north of Belgorod, which also borders Ukraine, said air defence systems destroyed at least four Ukraine-launched drones. He did not provide further detail on any potential damage.
On Tuesday, Ukraine said that a Russian missile slammed into two apartment buildings in the central Ukrainian city of Kryvyi Rih on Tuesday, killing three people and injuring at least 38, with President Volodymyr Zelenskiy vowing a response.
"We will inflict losses on the Russian state in response - quite rightly," Zelenskiy said in his nightly video address.
"They in the Kremlin should get used to the fact that terror does not go unpunished for them."
Ukraine has not claimed direct responsibility for the drone attacks on Tuesday and Wednesday.
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