Flights at major Moscow airports were disrupted on Friday after an early hours drone strike not far from the Kremlin.
Witnesses described a powerful explosion around a non-residential building in Moscow’s expo centre, three miles west of the Kremlin.
Russia’s air transport agency said seven flights were redirected after the strike forced the suspension of air traffic at four major airports around Moscow.
The Russian defence ministry blamed the attack on Ukraine, saying the drone was shot down by air defences. Officials said there were no casualties.
Remote-controlled strikes in Russia have increased since a drone was destroyed over the Kremlin in May. Ukraine has not responded to Russian accusations, including for two strikes near the Expo Centre in July.
At the time, Ukrainian president Volodymyr Zelensky said: “Gradually, the war is returning to the territory of Russia, and this is an inevitable, natural and fair process.”
But Mr Zelensky’s government is also demanding greater western air power to sustain its counter-offensive, after complaining that US-made F16 jets would not be arriving soon.
“At about 4 am Moscow time, the Kyiv regime launched another terrorist attack using an unmanned aerial vehicle on objects located in Moscow and the Moscow region," the Russian defence ministry said.
According to US media reports, United States intelligence agencies believed Ukrainian spies or military intelligence were behind the strike.
Since then, a series of drone strikes have struck Russia, including several buildings which were damaged on May 30 in the south west of Moscow.
On July 30 and 31, two other separate drones also crashed into the glass facade of a skyscraper just a few hundred metres from the Expo Center.