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.

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.