The Kremlin said on Tuesday that "Ukrainian militants" were still active in Russia's border region of Belgorod, a day after local authorities declared a counter-terrorism operation there to repel what they called a sabotage group from Ukraine.

In a call with reporters, Kremlin spokesman Dmitry Peskov said that Russia's military campaign in Ukraine had been launched to prevent such incursions and that more efforts were needed from the Russian side to prevent such incidents.

Kyiv has said it is watching the situation in Belgorod closely but "has nothing to do with it." (Reporting by Reuters Editing by Andrew Osborn)