Inside Ukrainian offensive pushing Russia back on front line where Starlink plays a key role

Figure caption, Watch: BBC follows Ukraine's Operation Vivaldi pushing Russia back on frontline

A Russian drone zips across the computer screen, startling the commanders keeping watch over the battlefield via a live stream in their bunker.

Cigarette in one hand, radio in the other, one of them calls in their own drone to bring it down and warns the soldiers below of the threat. The men are dangerously exposed, on the long walk across open ground from their front line positions. They are being replaced after three months forcing the Russians back.

This is part of Operation Vivaldi, a Ukrainian counter-offensive which they say has liberated 277 sq km (106 square miles) in the eastern Donbas region in recent months.