A Ukrainian drone has smashed into a building in central Moscow after Russian air defences shot it down, disrupting air traffic at all of the capital's civilian airports, Russian officials say.
A Reuters witness who was in the area described hearing "a powerful explosion".
Reuters images showed workers and emergency workers inspecting the damaged roof of a non-residential building hit by the drone.
The Russian defence ministry and Moscow Mayor Sergei Sobyanin said there were no casualties after air defences destroyed a drone that then fell on a non-residential building of Moscow's Expo Centre complex in the early hours of Friday.
The Expo Centre is a large spread of exhibition pavilions and multi-purpose halls, less than five kilometres from the Kremlin.
"At about 4am 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.
There was no immediate comment from Kyiv.
Air traffic was briefly suspended at four major airports around the capital - Vnukovo, Domodedovo, Sheremetyevo and Zhukovsky - although later they reopened.
Russia's air transport agency said seven flights were redirected to alternative airports.
Drone air strikes deep inside Russia have increased since a drone was destroyed over the Kremlin in early May.
Civilian areas of the capital were hit later in May and a Moscow business district was targeted twice in three days earlier this month.
Both Ukraine and Russia deny targeting civilians and civilian infrastructure in the almost 18-month war.
Ukraine typically does not comment on who is behind attacks on Russian territory, although officials have publicly expressed satisfaction with them.
The New York Times reported in May that US intelligence agencies believed Ukrainian spies or military intelligence were behind the drone strike on the Kremlin.
Russia invaded Ukraine in February 2022, sparking a war that has sown devastation across swathes of eastern and southern Ukraine, killed or injured hundreds of thousands and triggered the biggest rupture in Russia's ties with the West since the 1962 Cuban Missile Crisis.
