The Russian military said its anti-aircraft units had thwarted a Ukrainian "terrorist attack" early on Tuesday and downed drones targeting Moscow, but one drone, sent out of control by its units, struck the same high-rise tower hit earlier in the week.
Video obtained by Reuters showed several square meters of the building's glass facade high above the ground destroyed by the impact.
"On the night of August 1, an attempted terrorist attack by the Kyiv regime with lethal drones on targets in Moscow and Moscow region was thwarted," the Defence Ministry said in a statement on the Telegram messaging app.
Two drones, the Ministry said, had been downed in suburbs west of the city centre.
"Yet another (drone) was hit by radio-electronic equipment and, having run out of control, crashed on the territory of the complex of non-residential buildings at Moskva Citi," the ministry said, referring to a business centre in the capital.
Vnukovo airport, one of three major airports serving the capital briefly shut down, but later resumed full operations.
Emergency services, quoted by Tass news agency, said debris from the falling drone had been located and would be sent for technical expertise.
Earlier, Moscow Mayor Sergei Sobyanin said one of the drones targeting the capital had flown into the same tower at Moskva Citi that had been struck earlier in the week.
"One flew into the same tower at the Moskva Citi complex hit previously. The facade has been damaged on the 21st floor. Glazing was destroyed over 150 square metres."
Sobyanin said no injuries were reported.
Moskva Citi was hit by drone attacks last Sunday - one of several such incidents which have caused limited damage but generated widespread unease.
Kremlin spokesman Dmitry Peskov said the day following that incident that Ukrainian attacks on Moscow and other Russian targets were "acts of desperation" and that Russia was taking all measures possible to protect against strikes.
Ukraine rarely comments on incidents that take place on Russian territory in its war against Moscow, now in its 17th month.
But this week, in an oblique reference to drone attacks, Ukrainian President Volodymyr Zelenskiy said the war "is returning to the territory of Russia - to its symbolic centres and military bases".
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