"The Ukrainian attacks are an attempt to thwart the elections," Russian President Vladimir Putin said, Russian state media reported.
The Russian leader said his military would respond to a series of Ukrainian attacks on his country as voters cast their ballots in the presidential election.
"These blows by the enemy do not and will not go unpunished. I am sure that our people, the people of Russia, will respond to this with even greater unity," Putin told a meeting of his security council.
BGNES reminds that today the Russian police detained at least eight people for vandalism in polling stations on the first election day.
Authorities did not say whether the protests were directed at longtime leader Vladimir Putin, and state media said voting was "continuing as normal."
In Moscow, a video released by independent news agency SOTA showed an elderly woman setting fire to a voting booth and filling the polling station with smoke before being detained by police.
Another video in the capital shows a woman pouring paint into an urn. In St. Petersburg and the remote Siberian region of Khanty-Mansi, citizens tried to set fire to sections with a Molotov cocktail.
Earlier today, Russia's FSB security agency announced a wave of arrests of Russians who were "cooperating with Ukraine in planning attacks against Moscow." /BGNES