Ukrainian drone strikes have triggered fires at industrial facilities in Russia's Tula and Yaroslavl regions, according to their governors, with Ukrainian President Volodymyr Zelensky saying on Sunday the attacks were a response to Russia's refusal to end the war.
In the Tula region, south of Moscow, Governor Dmitry Milyaev reported that debris from a downed drone fell onto the site of a chemical plant in Novomoskovsk.
Unconfirmed video footage and reports emerged on social media showing a fire, suggesting that the Azot facility, one of Russia's largest chemical plants, was hit.
The site is important to the Russian war economy. It produces mainly fertilizer, but also components for the production of ammunition in defence industries.
The governor initially provided no details about the extent of the damage or possible health risks to the population.
In Oryol - around 350 kilometres west of Moscow - a drone struck a residential high-rise building, Governor Andrei Klychkov said. One person was killed in the targeted attack and eight others were injured, he said. The official also published photographs of the damage.
In the Yaroslavl region, Governor Mikhail Yevrayev spoke of a drone attack on industrial facilities used for fuel storage. A fire broke out, but there were no injuries, he said.
The Ukrainian SBU intelligence service said later on Sunday that several drones hit a fuel depot in Rybinsk, which is used as a state reserve.
The SBU stated that the fuel stored there, including petrol and diesel, was being used to supply the Russian army - and was therefore a legitimate target.
A video released by Zelensky showed a major fire with plumes of black smoke and drones flying overhead.
"Ukraine is carrying out its plan of long-range sanctions against Russia," Zelensky wrote on X. "We have offered the Russian leadership every possible format for negotiations – and the only response was continued aggression and attempts to expand it."
"It stands to reason that the war is coming back to where it came from," he added.
The Russian Defence Ministry said early on Sunday that a total of 249 aerial objects were shot down in various regions.
Moscow Mayor Sergei Sobyanin reported that several drone attacks had been repelled.
The capital's Zhukovsky Airport had to be closed due to an air raid alert. Restrictions were also in place at Domodedovo Airport.
Zelensky praised the strikes, saying attacks triggered air-raid alerts in 28 Russian regions.
Flight restrictions were in place at six airports, the Ukrainian president wrote.
Ukraine has been fending off the full-scale Russian invasion for more than four years. In recent months, it has stepped up long-range drone attacks on industrial facilities and refineries in Russia, targeting companies that are vital to the country's war effort.
There have been reports of shortages at petrol stations in Moscow and St Petersburg, as well as the central republic of Tatarstan.
The situation is particularly difficult on the Black Sea peninsula of Crimea, which Russia annexed in 2014. However, the Russian government insists that the situation is under control.
Moscow says troops advancing on Kostiantynivka
Russian forces are making further advances in street fighting in the eastern Ukrainian city of Kostiantynivka in the Donetsk region, the Defence Ministry in Moscow said on Sunday.
Forces have brought a further 100 or more buildings in the city under Russian control, the Moscow ministry said. In the south-west of the city, encircled units of the Ukrainian armed forces had been destroyed, it said.
Ukraine's military had recently acknowledged it was facing a difficult situation in the city.
The US-based Institute for the Study of War (ISW) in Washington said in an analysis that Ukraine's ability to defend Kostiantynivka was deteriorating. At the same time, the experts said that Moscow was using its detailed statements to create a greater impression of Russian presence than actually existed.
Kiev's leadership had recently been saying that it had halted the Russian advance and recaptured territory. Yet even Ukrainian maps show Russian forces advancing into the heavily destroyed industrial city, albeit more slowly than during the winter months.
Independent military observers consider it possible that Kostiantynivka could fall during the coming months. Putin would then be closer to his goal of bringing the Donbas completely under Russian control.
Of the larger cities in the Donetsk region, only Sloviansk, Kramatorsk and Druzhkivka would then remain under Ukrainian control.
The Russian Defence Ministry said that the advance of Moscow's forces into Kostiantynivka had prompted Ukraine to evacuate key facilities in the nearby cities of Kramatorsk and Druzhkivka.
Putin has said that complete control of the Donetsk region is a central war aim and a precondition for ceasefire negotiations.
