But they also faced a Russian advance in the northeast that created a dilemma about where to field available troops.

Ukrainian forces driving towards occupied Melitopol confirmed their recapture of Robotyne, an important Russian stronghold in western Zaporizhia, which they entered on August 20.

Southern forces spokesman Oleksandr Shtupun said on August 28 that forces were busy demining the area, securing their positions and winning more territory southeast of the settlement. Geolocated footage placed them 5km (3.1 miles) southeast of Robotyne.

Robotyne is important because it sits on the T0408, a highway used to resupply the Russian garrison in Tokmak, a key town 20km (12.4 miles) further south. Shtupun believed Russian forces would try to recapture Robotyne, fearing a rapid Ukrainian advance towards Tokmak.

Geolocated footage on August 27 showed elements of the Russian 76th Guards Air Assault (VDV) Division reinforcing positions in the area.

Ukraine’s Deputy Defence Minister Hanna Maliar said on August 28 that Ukrainian forces were already advancing on Novoprokopivka, the next settlement on the T0408, 4km (2.4 miles) south of Robotyne.

More worrying for some Russian military reporters was Ukraine’s reported advance towards Verbove, 8km (5 miles) east of Robotyne. One Russian military reporter called the situation there “very dangerous”.

Another Russian reporter said Ukrainian forces here were attacking towards Russian rear defensive lines, suggesting they may have nearly broken through the first belt of Russian defences.

“The series of defensive positions that Ukrainian forces are currently advancing through were comprised of dense layers of minefields and fortifications to which Russian forces committed considerable manpower, materiel, and effort to hold,” wrote the Institute for the Study of War (ISW), a Washington, DC-based think-tank.

Chairman of the US Joint Chiefs Mark Milley said that Ukraine was poised to advance through an array of anti-tank ditches, concrete anti-tank pyramids known as dragon’s teeth, anti-tank obstacles and additional minefields.

“There is a complex matrix of defensive preparations that the Ukrainians are now fighting to cross, and pass,” he told Jordan’s Almamlaka TV.

But, the ISW said, the extent of these minefields was unclear, and they might be sparser than the minefields Ukraine has already crossed “to give Russian forces operating north of these positions the ability to retreat”.

A Ukrainian commander who led troops into Robotyne told Reuters news agency that the counteroffensive had broken through the toughest Russian defences and would now move faster.

“We have passed the main roads that were mined. We are coming to those lines where we can go [forward]. I’m sure we’ll go faster from here,” said the commander, who had the call sign “Skala”.

Milley agreed, saying Ukrainian forces “have crossed the main first line of defence”.

The ISW cautioned that “there are additional series of prepared Russian defensive positions further south of the current Ukrainian advance”.

Shtupun said on August 27 that a separate counteroffensive spearhead driving towards occupied Berdyansk had also had unspecified successes near Staromaiorske, which Ukrainian soldiers recaptured on July 27.

The Russian “Vostok” Battalion’s Commander Alexander Khodakovsky said he was experiencing occasional shortages of manpower in the area.

“When there is not enough resources, we are stretched across a long arc and are experiencing difficulties with the transfer of reserves in a large circle,” he wrote on Telegram.

Ukrainian forces were also advancing in the east. Maliar said Ukrainian forces had pushed Russian forces out of Klishchiivka as they flanked the occupied city of Bakhmut to the south.

Ukrainian forces here had liberated a total of 44sq km (17sq miles) she said, a square kilometre more than the week before.

Russia’s response

Russia has responded to these Ukrainian advances in the south and east by launching a new offensive in the northeast, towards the city of Kupiansk.

Ukrainian Defence Minister Oleksii Reznikov confessed that Russian forces “seem to be making some progress there”, but that Ukraine would not be blindsided into diverting forces from its counteroffensive.

“It’s the enemy’s logical move to divert our attention by attacking there, so that we withdraw units from the south and east. But General Syrskii, who commands the Khortytsia troops, is simultaneously holding the defence on that front and counterattacking in the Bakhmut direction,” RBK-Ukraine quoted Reznikov as having said at a press conference.

Reznikov also said the Russian move was risky, because if Ukrainian forces advanced in Bakhmut, “they will be trapped there”.

But Khodakovsky said Ukrainian forces were torn between defence and counteroffence, and lacked the mass to follow through on their successful attacks, helping to explain their slow progress.

“Even if it is possible to achieve tactical success in places, there is no way to develop it, and the enemy is pulled back, fearing the environment,” he wrote.

The war in the air

Both Russia and Ukraine have continued to target each other’s weapons and logistics using drones and missiles.

A Ukrainian drone swarm targeted the Russian 126th Guards Coastal Defence Brigade (Black Sea Fleet) near Perevalne, in the Crimea, said Ukraine’s military intelligence spokesperson Andriy Yusov.

The Russian defence ministry said it downed all 42 drones, but Ukrainian residents throughout occupied Crimea said they heard many explosions, especially in Prevalne.

Ukraine has used drones to target the Russian rear before, but a swarm of 42 might be its largest-scale attempt to date.

Ukraine may also have successfully struck a Russian airfield on Russian soil.

RBK-Ukraine said Ukrainian SBU military counterintelligence used drones to attack an airfield near the city of Kursk on the night of August 27, damaging four Russian Su-30 fighter jets, one MiG-29 fighter jet and radars for an S-300 missile system, and two Pantsir missile systems.

Retired Australian Army Major-General Mick Ryan called the attacks “a demonstration of the evolving sophistication and capability of Ukraine’s conduct of strike operations” and said “Ukrainians are not only conducting attacks on an expanding list of targets but doing it at longer range”.