A drone launched by the Security Service of Ukraine (SBU) dropped an explosive on the power substation in the village of Snagost in Russia's Kursk region as a result of which seven settlements were left blacked out, a source in the Ukrainian special service told Interfax-Ukraine.

"The blackout in Russia's Kursk region was organized by the SBU… It was the special service's drone that dropped an explosive on the power substation in the village of Snagost, Kursk region. As a result, seven settlements were left blacked out," the source said.

The source also noted that "such a 'bavovna' [attack] shows the fact that the SBU's special operations have entered a new level."

"Russia should understand that if it is going to continue attacks on Ukrainian energy facilities, then it will receive a tough response. Our resources allow us to do this," the source said.