A Ukrainian drone attack has hit a building in Moscow, causing an explosion that was heard across the city’s business district, Russian officials have said.

Mayor Sergei Sobyanin said air defences had shot down the drone with its debris falling on the city’s Expo Center.

It marks the latest in a series of such attacks on the Russian capital.

Unverified footage on social media appeared to show thick grey smoke rising into the night sky over Moscow.

There was no immediate comment from Ukraine.