Ukraine is sending ground robots armed with grenade launchers into Russian positions instead of soldiers, its Third Army Corps said. The machines took part in Operation Vivaldi, a counteroffensive the corps made public on September 15.

Each robot carried two Bullspike grenade launchers, according to the corps. The vehicles approached Russian trenches, fired, then drove into the troops' shelters and detonated. Operators steered them remotely from protected sites tens of kilometres behind the front line.

In a separate tactic, heavy bomber drones dropped NC13 strike robots, nicknamed Gryphons, more than 10 kilometres behind Russian lines. The corps called it the first such airdrop of ground robots in the war.

The corps claims the campaign killed or wounded more than 3,000 Russian troops and retook 125 square kilometres of territory. Those figures have not been independently verified, though outside trackers confirmed several villages changed hands.

The tactics show how Ukraine is shifting frontline risk onto machines as the war grinds on through another year.