Russian forces in the Donetsk region town of Lyman were on Friday encircled by the Ukrainian military, overshadowing Vladimir Putin’s annexation of four Ukrainian regions.
The government in Kyiv urged Russian troops to lay down their arms and surrender as long-range Ukrainian weapons made it virtually impossible to reinforce or escape the town via the last remaining safe highway.
Heavy fighting was reported on the outskirts of Lyman, as separate Ukrainian forces advanced in a pincer movement designed to surround their enemy.
A military setback in the town, which has served as a key logistics hub for Russia’s operations in the Donbas, would be one of Moscow’s most significant failures of the war.
As Ukraine’s forces advanced on the town from three directions, the village of Yampil, directly south east, was liberated and Russia abandoned its forward defensive position in Drobysheve to the north.
Military officials largely maintained operational silence, but hinted that an attempt to fully encircle Russian forces in the area was under way.
“All the approaches and logistic routes of the enemy, through which they delivered ammunition and manpower, are in fact under control (of Ukraine),” Serhii Cherevatyi, a spokesman for eastern Ukrainian forces, said.
Mykhailo Podolyak, a senior aide to the Ukrainian president, said: “Russia will have to ask for an exit from the Lyman cauldron. Only if, of course, those banqueting in the Kremlin care about their soldiers.”
Oleksiy Goncharenko, a Ukrainian MP, tweeted: “Lyman is surrounded! The Ukrainian army is already in Yampil. The Russian army is trying to escape.”
Between six and seven thousand Russians were said to be dug in and defending their position in Lyman, a politically and strategically important town for both Moscow and Kyiv.
After videos emerged of Ukrainian troops in Yampil, about 10 and a half miles from the town in northern Donetsk, Russian military bloggers reported that the Kremlin’s forces had been pushed back to Lyman’s “administrative border”.
The pro-Kremlin sources said their armed forces faced certain defeat unless they were reinforced “as soon as possible”.
The Telegraph could not immediately verify their claims.
Denis Pushilin, the head of the so-called Donetsk People’s Republic, said Lyman was “half-encircled” with only one possible escape route.
He said Ukraine’s armed forces were “trying at all costs to spoil our historic event”, referring to Mr Putin’s illegal annexation of four Russian-occupied areas of the country.
“Our guys are fighting, we are pulling up reserves,” the pro-Kremlin separatist leader wrote on the Telegram messaging app, before attending an annexation ceremony in Moscow.
“We must hold out, but the enemy has also thrown serious forces [at Lyman]. This is very unpleasant news, but we must look soberly at the situation and draw conclusions from our mistakes.”
Mr Pushilin also claimed Russian troops were still be in control of the highway to Svatove, in the neighbouring Luhansk region – the only escape route from Lyman.
However, given Ukraine’s ability to bring accurate fire on to the highway, Moscow’s forces would likely sustain heavy losses if they attempt to flee through the narrow salient.
Russian forces captured Lyman in May, using the town as a staging post for the assault on the Donbas.
The fall of the town would be a military set-back for Moscow and bolster the Ukrainian push into occupied Luhansk, reversing Russian gains in the Donbas.
“Nothing will stop Ukrainian formations developing an offensive deep into Russian territory,” Rybar, an authoritative Russian blogger, wrote of the possible imminent defeat.
The claim was supported by Karolina Hird, a researcher for the US-based Institute for the Study of War, who said: “The collapse of the [Russian] pocket around Lyman may allow – depending on how Ukrainian forces decide to pursue further gains – to unhinge this line and open up potential further advances east.”
Having lost the towns of Izyum and Kupyansk earlier this month, defeat in Lyman would further demonstrate Russia’s inability to stabilise its defensive lines, ahead of an expected slowdown in the conflict through the winter months.
Justin Bronk, an air power analyst at the Royal United Services Institute defence think tank in London, said the encirclement of Lyman could prove to be “significant” both militarily and politically, given the Russian announcement earlier in the day.
“Any resultant large scale Russian personnel and materiel loss could further destabilise already fragile Russian military morale throughout Ukraine,” he added.