Shops and schools have been closed in the Russian city of Belgorod after bombardments that authorities there have blamed on Ukraine.
Belgorod governor Vyacheslav Gladkov said two people were killed – as voting continues in a general election Vladimir Putin is certain to win.
Air defence systems downed eight Ukrainian missiles, Gladkov said.
Putin accused Ukraine of trying to disrupt his bid for another six-year term.
Students in Belgorod – which is near the border with Ukraine – will not attend school on Monday and Tuesday, the governor said.
Shopping centres in Belgorod will be closed on Sunday and Monday, Gladkov added.
Gladkov said one woman was killed in a car park while with her son, as they walked a dog. “Medics are fighting for her son’s life,” the governor added.
Images circulating on social media show a car park billowing with smoke and fire. Belgorod has been the target of several retaliatory strikes from Kyiv.
The Russian defence ministry confirmed that it had “inflicted losses” in the border areas of Ukraine and the Belgorod and Kursk regions.
Also on Saturday, the governor of the Samara region – southeast of Moscow – said Ukrainian drones targeted two oil refineries.
In a post on Telegram, Dmitry Azarov said one of the refineries, in Syzran, had been set alight but there were no casualties.
A Ukrainian source told Reuters Kyiv’s SBU intelligence agency struck three Samara region Rosneft refineries – in Syzran, Novokuibyshevsk and Kuibyshevsk.
Kyiv has not commented about the attacks in Belgorod.