RUSSIA'S AIRSPACE, AIRPORTS CLOSED AFTER UKRAINE DRONE HIT CITY BUILDING. (PHOTO).

Russia's Airspace, Airports Closed After Ukraine Drone Hit City Building 

Air-traffic has been reopened at four major airports around the capital - Vnukovo, Domodedovo, Sheremetyevo and Zhukovsky.

Moscow's airspace has been closed after a Ukrainian drone attack on Friday hit a building causing a blast that was heard across the city’s business district, Russian state media agency TASS said.

Russian air defense in a statement said the drone changed it path after it was targeted by air defense weapon and fell on a non-residential building in the Krasnopresnenskaya Embankment area of Moscow on Friday morning. 

The statement reads: "The UAV (unmanned aerial vehicle), after being targeted by air defence weapons, changed its flight path and fell on a non-residential building in the Krasnopresnenskaya Embankment area of Moscow.

"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.”

According to Reuters, Air-traffic has been reopened at four major airports around the capital - Vnukovo, Domodedovo, Sheremetyevo and Zhukovsky.

Russia's air transport agency said seven flights were redirected to alternative airports. 

A witness who was in the area told Reuters it was "a powerful explosion".

Moscow mayor Sergey Sobyanin said on Telegram that "debris of the UAV fell down in the area of Expo centre," he said referring to a large exhibition space in central Moscow, about 3 miles away from the Kremlin. 

It "did not cause any significant damage to the building", he added.

A video published by Russian media outlets showed thick smoke rising next to skyscrapers. 

There has been no immediate comment from Kyiv.

The Russian defence ministry also claimed a separate attempted assault on its Black Sea fleet.

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.