Russia's Kazan airport has temporarily halted flight arrivals and departures, Russia's aviation watchdog Rosaviatsia said via the Telegram messaging app on Saturday, following a Ukrainian drone attack on the city.
Russian state news agencies reported the drone attack on a residential complex in Kazan, a city some 500 miles (800 km) east of Moscow. The TASS agency said eight drone strikes had been recorded including six on residential structures.
There were no casualties reported, agencies said, citing local authorities.
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.
Rosaviatsia said it was also introducing temporary restrictions at the airport in Izhevsk, a smaller city northeast of Kazan.
Meanwhile, Russia attacked Ukraine with 113 drones overnight, the Ukrainian air force said on Saturday, adding that it downed 57 of them while 56 others failed to reach their targets.
The air force said Russia also fired one S-400 missile at central Ukraine but that there was no damage from it.
Moscow launches near-daily attacks with dozens of drones at Ukraine in an effort to exhaust its air defences.