While the ground war in eastern Ukraine has settled into a grinding war of attrition, where Russian forces sacrifice hundreds, sometimes thousands, of troops a day, for small, incremental advances, the air war has the two sides inflicting significant losses on each other's energy sector.

Ukraine downed 34 out of 55 drones launched by Russia in an overnight attack, the Ukrainian air force said on Thursday, with a further 18 failing to reach their targets, something which usually indicates they were jammed by electronic warfare.