Residents of two villages in Russia’s Belgorod region on Ukraine’s northeastern border were evacuated after a fire at a nearby munitions depot.
The blaze is the latest in a series of destructive incidents on Russian-occupied territory in Ukraine or inside Russia itself.
Roughly 1,100 people live in the villages of Timonovo and Soloti, around 15 miles (25km) from the Ukrainian border.
There were no casualties in the fire, which happened late on Thursday, the Belgorod region’s governor Vyacheslav Gladkov said.
The blaze comes days after another ammunition depot exploded on Ukraine’s Black Sea peninsula of Crimea, a Russian-occupied territory seized by Moscow in 2014.
Nine Russian warplanes were reportedly destroyed at an airbase on Crimea last week, demonstrating both Russia’s vulnerability and Ukraine’s capacity to strike deep behind enemy lines. Ukrainian authorities have stopped short of publicly claiming responsibility.
But Ukrainian president Volodymyr Zelensky alluded to Ukrainian attacks behind enemy lines after the blasts in Crimea, which Russia has blamed on “sabotage”.
Russia’s deputy foreign minister Sergei Ryabkov said in televised remarks on Friday that statements from Ukrainian officials about striking facilities in Crimea marked “an escalation of the conflict openly encouraged by the United States and its Nato allies”.
Mr Ryabkov said Russian officials had warned the US against such actions in phone calls with high-level members of the Biden administration, adding that “deep and open US involvement” in the war in Ukraine “effectively puts the US on the brink of becoming a party to the conflict”.
“We don’t want an escalation, we would like to avoid a situation where the US becomes a party to the conflict, but so far we haven’t seen their readiness to deeply and seriously consider those warnings,” he added.
Meanwhile, Kyiv and Moscow continued to accuse each other of shelling Europe’s largest nuclear power plant, stoking international fears of a catastrophe on the continent.
The Kremlin said on Friday that Russian president Vladimir Putin told French counterpart Emmanuel Macron in their first phone conversation since May 28 that Ukrainian shelling around the Zaporizhzhia nuclear power plant “raised the threat of a large-scale catastrophe that could lead to radioactive contamination of large territories”.
The Zaporizhzhia nuclear facility in Ukraine’s south has been controlled by Russian forces since shortly after the invasion began on February 24.
Ukraine has accused Russia of storing troops and weapons at the Zaporizhzhia plant and using its grounds to launch strikes against Ukrainian-controlled territory.
Ukrainian officials and military analysts say Moscow’s forces have cynically employed the plant as a shield, knowing that the Ukrainians would be hesitant to fire back.
Russia has denied the accusations and, in turn, accused Ukrainian forces of repeatedly shelling the plant.
The French presidency said in a statement that Mr Macron “underlined his concerns” regarding the situation at the Zaporizhzhia plant and expressed his support for the deployment of an International Atomic Energy Agency (IAEA) mission to the site “as soon as possible”.
Mr Putin agreed to the mission’s deployment under the discussed terms, according to the French statement. The Kremlin said that “the Russian side reaffirmed its readiness to offer the necessary assistance to the agency’s experts”.
Following a visit to Ukraine on Thursday, Turkish president Recep Tayyip Erdogan said that Mr Zelensky had asked him to ensure that Russia removed weapons stored at the plant as an “important step for world peace”.
“Zelensky asked this of us especially: that Russia remove all mines and similar (weapons) there and for the issue to rapidly cease to be frightening. Because it is a threat,” Mr Erdogan said.
Mr Erdogan, whose country has maintained close relations with both Ukraine and Russia, said he would discuss the issue with Russian president Vladimir Putin, saying that “Russia must do its part in this regard”.
The Turkish president made the comments to a group of Turkish journalists on his return from a visit with Mr Zelensky and UN Secretary-General Antonio Guterres in Ukraine late on Thursday.
At the meeting in the western city of Lviv, far from the front lines, the leaders discussed expanding exchanges of prisoners of war and arranging for UN atomic energy experts to visit and help secure the nuclear power plant.
Yevgeny Balitsky, the Moscow-backed chief of temporary administration for the Russia-controlled part of the Zaporizhzhia region, said on Friday that a mission from the IAEA could approach the plant from Ukrainian-held territory, a shift in Moscow’s position which previously had suggested that the agency’s mission should travel to the plant from Crimea.
“I believe they may also come from the side of Ukraine,” Mr Balitsky said. “We can safely bring them to the plant and show where the fire is coming from and who is shooting.”
Mikhail Ulyanov, the Russian envoy to international organisations in Vienna where the IAEA is based, said he believed a visit by the agency could realistically take place in early September.
Meanwhile, at least five people were killed and 10 others were wounded by the Russian shelling of towns and villages in Ukraine’s eastern Donetsk region, according to regional authorities.
The shelling damaged residential buildings and civilian infrastructure in the embattled region where Russian forces are pushing to overtake areas still held by Ukraine.
And at least one civilian died early on Friday in Russian shelling of the city of Kharkiv, to the northwest of the Donetsk region, while Russian missiles in the southern port city of Mykolaiv again struck port facilities and a university building that was previously hit by shelling earlier this week. One person was wounded in the attacks, authorities said.