Dark smoke could be seen from many miles away after the attack on two outlying districts of Kyiv early on Sunday. Moscow said it had hit a repair shop housing tanks sent from eastern Europe.
Ukraine said Russia had carried out the strike using long-range air-launched missiles fired from heavy bombers as far away as the Caspian Sea, a weapon far more valuable than the tanks Russia claimed to have hit.
At least one person was hospitalised but there were no immediate reports of deaths from the strike, a sudden reminder of war in a capital where normal life has largely returned since Russian forces were driven from its outskirts in March.
"The Kremlin resorts to new insidious attacks. Today's missile strikes at Kyiv have only one goal - kill as many as possible," Ukrainian presidential adviser Mikhailo Podolyak wrote in a tweet.
Ukraine's nuclear power operator said a Russian cruise missile had flown "critically low" over the country's second largest nuclear power plant.
The attack was the first big strike on Kyiv since late April, when a missile killed a journalist.
Recent weeks have seen Russia focus its destructive might mainly on frontlines in the east and south, although Moscow occasionally strikes elsewhere in what it calls a campaign to degrade Ukraine's military infrastructure and block Western arms shipments.
Russia has concentrated its forces in recent weeks on the small eastern factory city of Sievierodonetsk, launching one of the biggest ground battles of the war in a bid to capture one of two eastern provinces it claims on behalf of separatist proxies.
After retreating steadily in the city in recent days, Ukraine mounted a counterattack there, which it says took the Russians by surprise.
After recapturing a swathe of the city, Ukrainian forces were now in control of half of it and continuing to push the Russians back, said Serhiy Gaidai, governor of the Luhansk region that includes Sievierodonetsk.
"It had been a difficult situation, the Russians controlled 70 per cent of the city, but over the past two days they have been pushed back," Gaidai said on Ukrainian TV. "The city is now, more or less, divided in half."
The claims could not be independently verified. Both sides say they have inflicted huge casualties in Sievierodonetsk, a battle that could determine which side carries the momentum into a protracted war of attrition in coming months.
Britain's defence ministry said on Sunday that Ukrainian counterattacks there over the past 24 hours were likely to blunt any operational momentum that Russian forces had previously gained.
Russia was deploying poorly equipped separatist fighters in the city to limit the risk to its regular forces, it said.
Moscow said its own forces were making gains in the city. Ukraine's army said Russian forces continued to mount assault operations with the aid of artillery and controlled the eastern part of Sievierodonetsk.
In neighbouring Donetsk province, which Moscow also claims on behalf of its separatist proxies, Russian forces have been advancing in recent days in territory north of the Siverskiy Donets river, in advance of what Ukraine anticipates would be a push on the major city of Sloviansk.
Ukrainian officials said at least eight people were killed and 11 injured in Russian shelling in the province overnight.
In an interview with Russian state TV, President Vladimir Putin said Moscow would hit new targets if the West supplies longer-range missiles to Ukraine.
