Russian mercenery organisation Wagner Group on Saturday claimed that it controls the city of Bakhmut in Eastern Ukraine.
The Battle of Bakhmut has been the longest in the ongoing Ukraine War and has seen some of the most intensive fighting in recent month. The control of Bakhmut would serve as a significant symboli victory for the Russians, who had devoted considerable resources to it.
In a video posted on Telegram, Wagner Group chief Yevgeny Prigozhin said Bakhmut came under complete Russian control at about midday on Saturday. Ukrainian officials have denied the claim.
However, after the video appeared, Ukrainian deputy defence minister Hanna Maliar said heavy fighting was continuing.
She said, "The situation is critical. As of now, our defenders, control certain industrial and infrastructure facilities in this area."
Serhiy Cherevatyi, spokesman for Ukraine's eastern command, told The Associated Press that Prigozhin's claim "is not true".
"Our units are fighting in Bakhmut," said Cherevatyi.
Fighting has raged around Bakhmut for more than 200 days. The Wagner Group has helmed much of the fighting in and around Bakhmut for Russia and Prigozhin has been vocal in highlighting his group's achievement and criticising the Russian defence ministry.
While there is no independent confirmation of the control, Russian forces reportedly made gains in recent days. Sky News on Friday reported that Russia controlled 95 per cent of the buildings in Bakhmut.
"Although Ukraine has made small gains in the open ground around the flanks, its hold inside the city is looking increasingly desperate. Russia has captured at least 95 per cent of the buildings and is still pushing forward," reported Sky.
The grinding war of attrition at Bakhmut has destroyed large parts of the city and has taken a massive toll on both sides.
"The tragedy of Bakhmut is that the battle is not about seizing vital ground - it is about maximising enemy casualties. The fall of Bakhmut will not bring the end of the war any closer, nor will it have moved the front-line substantially," reported Sky earlier this month.
If Russian forces have taken control of Bakhmut, they will still face the massive task of seizing the remaining part of the Donetsk region still under Ukrainian control, including several heavily fortified areas.
It is not clear which side has paid a higher price in the battle for Bakhmut. Both Russia and Ukraine have endured losses believed to be in the thousands, though neither has disclosed casualty numbers.
Ukrainian President Volodymyr Zelenskyy underlined the importance of defending Bakhmut in an interview with The Associated Press in March, saying its fall could allow Russia to rally international support for a deal that might require Kyiv to make unacceptable compromises.
Analysts have said Bakhmut's fall would be a blow to Ukraine and give some tactical advantages to Russia but wouldn't prove decisive to the outcome of the war.
Russian forces still face the enormous task of seizing the rest of the Donetsk region under Ukrainian control, including several heavily fortified areas. The provinces of Donetsk and neighboring Luhansk make up the Donbas, Ukraine's industrial heartland where a separatist uprising began in 2014 and which Moscow illegally annexed in September.
(With AP inputs)