Russian state news agencies reported the drone attack on a residential complex in Kazan, the capital of the Tartarstan republic, and a city some 800 km east of Moscow.

The Defence Ministry said the city had been attacked by three waves of drones between 07:40 and 09:20 local time in the morning.

There were no casualties reported, agencies said, citing local authorities. The mayor of Kazan said on Telegram that all planned mass events in the city would be cancelled over the weekend and that authorities would offer temporary accommodation to evacuees.

The Baza Telegram channel, which is close to Russia's security services, published unverified video footage showing an aerial object crashing into a high-rise building, producing a large fireball.

The Kazan airport temporarily halted flight arrivals and departures, Russia's aviation watchdog Rosaviatsia said via Telegram.

Rosaviatsia said it was also introducing temporary restrictions at two other airports, in Izhevsk, a smaller city northeast of Kazan, and in Saratov, which lies some 650 km south of Kazan. The restrictions at Saratov were later lifted.

According to Russia media, the drones used were called “Lyuty,” which have a flight range of around 1000km with a combat payload of up to 50 kg.

The Ukrainian authorities have not commented on the drone attack in Kazan thus far.

A series of explosions also took place in the resort city of Sochi, east of the Black Sea. Residents of the city reported on social media that there were about ten explosions in one of the districts in the morning, which caused tremors and set off car alarms.