Russian mercenaries are in full control of the Ukrainian city of Bakhmut, their chief says – a claim immediately dismissed by Ukrainian officials.
“We took the whole city,” said Yevgeny Prigozhin, posing with some of his Wagner fighters.
Ukraine’s deputy defence minister rejected the claim but admitted the situation was “critical”.
Wagner mercenaries have been leading efforts to take the eastern city and previously claimed to have seized it.
Bakhmut is of little strategic importance to Russia, which has been trying to capture it for months.
Ukraine, for its part, has also decided to make a stand in a battle which has become the longest and bloodiest of the war so far.
Mr Prigozhin – a close ally of Russian President Vladimir Putin – leads the thousands-strong Wagner group, nominally a private military company.
He has claimed before that his forces have taken Bakhmut – or most of it – only for Ukrainians to swiftly deny the claims. Mr Prigozhin has also targeted top Russian military officials, criticising them publicly for not supplying his troops with enough ammunition.
In his latest video claiming control of Bakhmut, Mr Prigozhin said “no-one can pedantically reproach us for the fact that at least some piece was not taken”.
Explosions can be heard in the background, suggesting fighting continues close to the city, if not inside it.
He also promised to hand the city over to regular Russian troops later in the month.
His claims were echoed by the Russian defence ministry on Saturday night, state media in Moscow reported.
But in a statement on the messaging platform Telegram moments afterwards, Ukrainian Deputy Defence Minister Hanna Maliar said: “Heavy fighting in Bakhmut. The situation is critical.
“As of now, our defenders control some industrial and infrastructure facilities in the area and the private sector.”
Western officials estimate between 20,000 and 30,000 Russian troops have been killed or wounded in Bakhmut, while Ukraine’s military has also paid a heavy price.
There is hardly a building left unscathed, and the city’s entire population has vanished.
The latest Wagner claim came as Ukrainian President Volodymyr Zelensky went to Japan to attend a meeting of the leaders of the world’s most industrialised countries, the G7.
His Western allies pledged more support, including taking a significant step towards providing F-16 fighter jets, and announced more sanctions on Russia.
Russian troops invaded Ukraine on 24 February last year and control parts of its east.
Ukraine has been expected to launch an offensive to retake seized territories, but Mr Zelensky recently said that more time is needed to prepare.
He has called Bakhmut “a fortress” of Ukrainian morale.
Ukraine’s hope is that the fight over Bakhmut has blunted Russia’s ability to conduct its own offensive operations, and exhausted its army and supplies.