Russia has temporarily shut three checkpoints on Crimea’s border with Ukraine amid reports that acts of sabotage could have left part of the peninsula without power and gas supplies.

Russia annexed the Black Sea peninsula in March 2014 from Ukraine, after an internationally condemned referendum. Ukraine considers Russia’s presence in Crimea an illegal occupation.

An unnamed Federal Security Service (FSB) border official in Crimea told the news agency Interfax on Wednesday that three border checkpoints — Armyansk, Dzhankoi and Perekop — had suspended their work “for technical reasons.”

In a separate report, Sergei Aksyonov, the head of the local government, wrote on Facebook that an electricity pole had been brought down and several settlements along the southern Crimean shore were left without gas supplies overnight.