Russia carried out its largest missile attack in weeks on Ukraine on Thursday, targeting energy facilities in what officials say is part of the first new air campaign against the Ukrainian power grid since last winter. Power cuts were reported in five Ukrainian regions, along with multiple civilian deaths.

But beyond the significance of the casualties and targets, experts are also pointing to the weapons employed. An attack in Kupyansk, in Ukraine's Kharkhiv region on Tuesday suggests that Russia has begun using a new missile system that exhibits formidable destructive potential and the ability to bypass Western air defense systems.

The Sept. 19 attack killed eight people. Oleg Sinegubov, the head of the local administration, provided a sobering account of the incident: “Two of the dead were volunteers who helped with evacuation efforts,” he said. “The occupiers cynically struck with the new Grom-E1 missile.”