Russia's grinding battlefield gains seen driven by new tactics

It took Russia weeks of fierce fighting, an untold number of casualties, and relentless shelling before the exhausted Ukrainian defenders of Sievierodonetsk received orders to quit its smouldering wreckage.

"Remaining in positions smashed to pieces over many months just for the sake of staying there does not make sense," Serhiy Gaidai, governor of the wider region, said on Ukrainian television on Friday.

With a reported 90 percent of the industrial city's buildings damaged, most of its around 100,000 residents long gone, and with limited strategic value beyond a sprawling chemicals plant, it does not look like much of a prize.

But its capture, confirmed by both sides on Saturday, is likely to be hailed by Russia as evidence that its switch from its early and unsuccessful attempts at "lightning warfare" to a much slower grinding offensive which relies more on long-range shelling rather than close-quarters combat, is paying off.

Sievierodonetsk would be the biggest Ukrainian city Russia has captured since it took the port of Mariupol last month.

"Our military has changed tactics," said one Russian government official.

"They know how to do it now. Yes it's slow, but the strategy works, and it means far less casualties," said the official, who declined to be named because they were not authorised to speak on the subject.

Konrad Muzyka, a Poland-based military analyst, said the tactical change meant Moscow could commit fewer troops to offensives amid unconfirmed Western suggestions that Russia is experiencing manpower problems.

"Whatever they did, it is working for them," said Muzyka.

"Another thing is we don't know what's going on with the Ukrainians; their manpower, losses and so on. From their point of view officially, everything is rosy. But it certainly is not this way."

Moscow calls its invasion, which began on Feb. 24, a "special military operation" to protect Russian speakers from Ukrainians intent on taking Kyiv into Nato, a move Russia says it cannot accept.

The West and Ukraine say Russia is waging an unjustified war of aggression designed to halt Kyiv's legitimate westwards drift and accuse the Kremlin of trying to recreate parts of the Russian Empire.

'First World War approach'

The fall of Sievierodonetsk leaves only one other major settlement in Ukraine's Luhansk region outside the control of Russia and its proxies - the nearby twin city of Lysychansk, which lies across the Siverskyi Donets River and on high ground, making it harder to overwhelm.

Luhansk is one of two regions which make up the wider Donbas area whose capture by Russian forces on behalf of proxy separatists is framed by Moscow as one of its main aims.

Ukrainian analysts say Kyiv is forcing Russia to pay a high price for its creeping progress.

- Reuters