Russia said on Monday it had downed nine Ukrainian drones that tried to attack part of the infrastructure of the TurkStream gas pipeline, through which Russian gas flows to Turkey and Europe, and called the attack an "act of energy terrorism".

Ukraine struck Russian regions with a major drone and missile attack overnight, damaging at least two factories and forcing schools to close in a major southern Russian city, according to Russian officials and media.

Russia accused Ukraine on Monday of launching a weekend drone attack on infrastructure of a major gas pipeline that carries Russian supplies to Europe via Turkey.