Russian oil refineries have stepped up security measures over the past few months - Russian Deputy PM Alexander Novak

 Russian oil refineries have stepped up security measures over the past few months, said Russian Deputy Prime Minister Alexander Novak.

"Our companies are allocating funds and coordinating with the Russian Ministry of Defense. These represent significant costs for energy facilities, but it is worth it, as refinery downtime results in heavy losses," he said.

Currently, about 10% of Russia's oil refineries are undergoing maintenance.

At the same time, the scheduled summer maintenance for all refineries has been postponed to a later date to ensure maximum fuel output for the domestic market.