Russian state news agencies reported the drone attack on a residential complex and other areas in Kazan, some 500 miles (800 km) east of Moscow.
The Defence Ministry said the city had been attacked by three waves of drones between 7:40 a.m. and 9:20 a.m. (0440 and 0620 GMT). It said three drones were destroyed by air defence systems and three others by electronic warfare systems.
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 canceled 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.
Russian foreign ministry spokeswoman Maria Zakharova condemned the attack, saying Ukraine was “taking out its impotent anger for real military defeats on the peaceful population of Russia”.
Airports in Izhevsk, a smaller city northeast of Kazan, and Saratov, some 400 miles (650 km) south of Kazan, had also temporarily halted flight arrivals and departures, Russia’s aviation watchdog Rosaviatsia said via Telegram.
Restrictions at the airports were later lifted, Rosaviatsia said.