Russia's defence ministry said Sunday it had repelled a "massive" Ukrainian drone attack across 14 regions and the capital that targeted energy and fuel plants.
Ukraine has repeatedly attacked Russia with drones, targeting energy infrastructure in retaliation for Moscow's missile attacks that have hugely damaged its own energy network.
"It is entirely justified for Ukrainians to respond to Russian terror by any means necessary to stop it," President Volodymyr Zelensky wrote on Facebook.
Moscow mayor Sergei Sobyanin said that 10 drones had targeted various areas of the capital.
A coal-fired power plant near the city was reportedly targeted, and an attack caused a fire at an oil refinery within the city boundaries.
The barrage comes just days after Ukraine's energy infrastructure was targeted by over 200 Russian drones and missiles in one of the biggest such attacks.
It is also nearly a month since Ukraine went on the offensive in Russia's Kursk region, even as Russian troops continue their steady advance in eastern Ukraine.
Russian authorities reported a fire at the Moscow oil refinery, owned by Gazprom, in southeast Kapotnya after it was targeted by drones.
Sobyanin said Sunday morning that a downed drone had hit a "technical building" at the plant and caused a fire.
An emergency services source told TASS state news agency that fuel was burning at the plant and the fire was initially classed as the highest level of complexity.
Sobyanin later said "the fire at the oil refinery has been localised and there is no threat to people or the plant's operation".
In the Tver region northwest of Moscow, five drones targeted the area of Konakovo power plant and caused a fire that was swiftly extinguished, according to governor Igor Rudenya.
"Gas and electricity supplies to the district are being carried out normally," he added.
Local media posted witness videos of a fire burning next to the plant's main building in the early morning after several drones circled the plant. AFP could not immediately verify their authenticity.
A local official in the Moscow region, Mikhail Shuvalov, said three drones had also tried to hit the Kashira coal-fired power station.
"There were no victims nor damage and it did not catch fire," he wrote on Telegram, adding that electricity was being supplied to customers as normal.
Russia's defence ministry said most of the 122 drones were downed over the regions of Kursk, Bryansk, Voronezh and Belgorod which border Ukraine.
In the Belgorod region, governor Vyacheslav Gladkov said: "The glass of three residential buildings in Belgorod is damaged. In one private residence, a utility building was completely destroyed."
Russian military blogger Rybar, who is followed by more than 1.3 million people, wrote, "the night attack by the Ukrainian armed forces was the most massive since the start of the special military operation" in 2022.
In the Donetsk region, Russia is advancing towards the city of Pokrovsk and Ukraine's Commander-in-Chief of the Armed Forces Oleksandr Syrsky wrote on Facebook that the "situation is difficult in the direction of the enemy's main offensive".
At least three people were killed and nine injured by shelling of the Donetsk region near the town of Kurakhove, the regional governor Vadym Filashkin said.
Russia on Sunday struck Ukraine's second largest city of Kharkiv with missiles, injuring 41 people including five children, in an attack targeting civilian infrastructure, said governor Oleg Synegubov.
The attacks targeted a large sports centre, a shopping centre and a park area, he said.
"Russia is once again terrorising Kharkiv, striking civilian infrastructure and the city itself," Zelensky wrote on Facebook, appealing for more weapons to fend off attacks.
He urged global leaders to show the "courage to give Ukraine everything it needs to defend itself".
