Russia blames nuclear site attack on Ukraine as Kyiv marks independence day
There were no injuries and the fire was quickly extinguished, the plant's press service said on messaging app Telegram.
Russia has blamed Ukrainian drone attacks for a fire at a nuclear power plant in its western Kursk region, saying several Russian power and energy facilities had been targeted overnight.
According to the BBC, there were no injuries and the fire was quickly extinguished. It said the attack had damaged a transformer, but radiation levels were within the normal range.
Firefighters were also sent to a blaze at the port of Ust-Luga in Russia's Leningrad region, which holds a large fuel export terminal.
The regional governor said about 10 Ukrainian drones were brought down and debris had sparked the fire.
Ukraine has not commented on the Russian accusations.
The United Nations' International Atomic Energy Agency (IAEA) said it was aware of reports regarding the fire, while its director general added that "every nuclear facility must be protected at all times".
The IAEA has repeatedly called on both Russia and Ukraine to show maximum restraint around nuclear facilities in the war.
It comes as Ukraine celebrates its independence day on Sunday, which marks the country's declaration of independence from the Soviet Union in 1991.
President Volodymyr Zelensky said Ukraine would continue to fight for its independence, in a video address early on Sunday.
He said: "We need a just peace, a peace where our future will be decided only by us."
Ukraine would "not wait for gestures of goodwill," he added: "When Russia wants to take Sumy region, then our armed forces appear in Kursk region.
"When the enemy strikes our energy system, wanting to leave us without light and heat, then its oil refineries burn.
"And so justice strikes, so Ukraine strikes when its calls for peace are not heard."
He continued: "Ukraine has not yet won, but it has certainly not lost."
US envoy Keith Kellogg was in attendance at Independence Day celebrations in Kyiv, Zelensky said, while Canada's Prime Minister Mark Carney arrived in the city on Sunday morning to meet the Ukrainian president. The pair are expected to hold a joint press conference.
"On this special day - Ukraine's Independence Day - it is especially important for us to feel the support of our friends. And Canada has always stood by us," Andriy Yermak, Zelensky's chief of staff, wrote on Telegram.
Meanwhile, Zelensky shared a letter from King Charles sending the people of Ukraine his "warmest and most sincere wishes".
"I keep feeling the greatest and deepest admiration for the unbreakable spirit of the Ukrainian people," the King writes. "I remain hopeful that our countries will be able to further work closely together to achieve a just and lasting peace."
Zelensky said the King's "kind words are a true inspiration for our people during the difficult time of war".
