Fierce fighting is raging for control of the centre of Bakhmut in eastern Ukraine, the longest-running and bloodiest battle of Moscow’s invasion, Russian and Ukrainian forces said on Monday.

Russia’s Wagner mercenary group has claimed to be leading Moscow’s charge for the industrial city, which has been the epicentre of fighting for months.

The Ukrainian military said: “Wagner assault units are advancing from several directions, trying to break through our troops’ defensive positions and move to the centre of the city.”

“In fierce battles, our defenders are inflicting significant losses on the enemy,” it said in a morning briefing.

Analysts are divided over the strategic significance of Bakhmut as a military prize but the city has gained important political stature, with both sides pouring significant resources into the fight.

Wagner head Yevgeny Prigozhin also acknowledged that his forces were experiencing determined resistance as they seek to capture the centre of the city.

“The situation in Bakhmut is difficult, very difficult. The enemy is battling for every metre,” he said in a post on social media.

“The closer we are to the city centre, the more difficult the battles get and the more artillery there is… Ukrainians are throwing endless reserves (at the fight),” Prigozhin said.