The Russian military said on Friday it had shot down a Ukrainian missile over the southern Russian city of Taganrog and that fragments of the missile had injured civilians and damaged buildings.
There was no immediate reaction from Ukraine, which rarely comments on attacks inside Russia or on Russian-controlled territory.
Vasily Golubev, governor of Russia's Rostov region, which includes Taganrog and is close to Ukraine, said a cafe had been hit along with a museum and that the windows of a residential building had been blown out.
He said nine people had been taken to hospital with injuries but that nobody had been killed.
Videos from the scene, circulating online, showed a low-rise building partly reduced to rubble.
Separately, an explosion was reported to have hit an oil refinery in the Russian city of Samara.
Alleged perpetrator arrested for the attack
Member of parliament Alexander Khinshtein said the explosion at the refinery owned by Rosneft appeared to have been caused by a bomb. "Fortunately there is no serious damage and no casualties," he said on Telegram.
The TASS news agency reported that a person believed to have been responsible for the blast had been detained.
Parts of Russia, especially near the border with Ukraine, have often been hit by shelling or drone attacks in the course of the 17-month war. Energy installations and weapons stores have been frequent targets.