Speaking to members of Russia's security council, which includes military and spy chiefs as well as the most powerful civilian leaders in the state, Putin said such crimes would not be left unpunished.
"In order to disrupt the voting process and intimidate people, at least in the border areas, the Kyiv regime... is trying to carry out a number of criminal actions - striking at civilian settlements in Russia," Putin said.
"These enemy strikes shall not remain unpunished," a visibly angry Putin said.
Putin said 95% of the shells and missiles were shot down by Russian air defences but said some got through and that there were casualties among Russian civilians.
Putin said there had been four attacks on the Belgorod region and one attack on the Kursk region by armed Ukrainian proxies numbering about 2,500. He said they had 35 tanks and 40 armoured vehicles.
Putin said about 60% of the Ukrainian-backed soldiers had been killed and half of their armoured vehicles lost.
"I am sure that our people, the people of Russia, will respond to this with even greater solidarity. Who did they decide to intimidate? The Russian people?" Putin said.
(Reporting by Reuters; Writing by Guy Faulconbridge; Editing by Andrew Osborn)
