The Ukrainian Navy said on Monday it had struck a thermal power plant in Russia's Oryol region and an electrical substation in Novobryansk, Reuters reported, quoted by BTA.
Neptune cruise missiles were used in the attack.
"Both facilities supplied electricity to military enterprises in the region, so their destruction is a serious blow to (Russian) logistics," the statement published on "Telegram" said.
Ukraine typically uses drones to strike targets deep inside Russia, but Kiev is also seeking to build up missile capability, relying on Ukrainian-made weapons such as missiles "Neptune", Reuters notes.