Almost daily long-range attacks on Russian oil facilities have created a fuel crisis and heaped political pressure on the Kremlin as its all-out invasion of Ukraine stretches into its fifth year.
The Ufa refinery is one of Russia's largest producers of lubricants and is located more than 1000km from Ukraine, Zelenskiy said on social media.
Ukraine also struck a plant producing missile components in Russia's Penza region southeast of Moscow, some 500km from Ukraine, Zelenskiy said.
Russian officials did not confirm the strikes, which could not be independently verified.
The Russian Defence Ministry reported intercepting 179 Ukrainian drones over 16 Russian regions, the annexed Crimea and waters of the Azov and the Black Sea.
Penza regional Governor Oleg Melnichenko said Ukrainian drones struck two industrial plants in the city of Penza, injuring two people at one of them. He didn't name the plants or describe the damage.
The explosions shattered windows in two apartment buildings in Penza, Melnichenko said, while downed drone debris damaged a powerline and fell on a building under construction.
Ukraine's domestically developed and manufactured drones and missiles have been hammering Russian oil facilities, including refineries, terminals, storage depots and pipeline pumping stations, for months.
Many regions of Russia, one of the world's biggest energy producers, have introduced fuel rationing.
Ukraine has developed new weaponry and in recent months has gained an edge, according to Western officials. Its strikes on supply routes behind the frontline have robbed the Russian army of momentum on the battlefield, officials and analysts say.
"Russians now have great problems with delivering infantry to the front line and supplying it," Ukrainian Minister of Defence Mykhailo Fedorov said.
Russian long-range attacks on Ukraine continued with drones targeting Kyiv, injuring five people as they hit residential buildings and triggered a fire in a hotel on a central boulevard.
Kyiv Mayor Vitali Klitschko, writing on Telegram, said the hotel roof was on fire on the central Shevchenko Boulevard.
Pictures posted online showed a fire burning out of control at the top of the building.
Multiple explosions were heard in Kyiv, a Reuters witness said.
People were trapped in a damaged nine-storey residential building and a roof of another high-rise apartment building was on fire, Klitschko added.
Other pictures on unofficial Telegram channels showed residents crowding into underground stations.
Zelenskiy had earlier warned intelligence reports showed an overnight attack on the country was likely and said he was cutting short his stay in Dublin, which he visited for the start of Ireland's six-month term in charge of the rotating presidency of the EU.
with Reuters
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