KYIV, Ukraine (AP) Russias advance seems to have stalled in Moscows campaign to capture the eastern Ukrainian city of Bakhmut , a leading think tank said in an assessment of the longest ground battle of the war .

The Washington-based Institute for the Study of War said there were no confirmed advances by Russian forces in Bakhmut. Russian forces and units from the Kremlin-controlled paramilitary Wagner Group continued to launch ground attacks in the city, but there was no evidence that they were able to make any progress, ISW said late Saturday.

The report cited the spokesperson of the Ukrainian Armed Forces Eastern Group, Serhii Cherevaty, who said that fighting in the Bakhmut area had been more intense this week than the previous one. According to Cherevaty, there were 23 clashes in the city over the previous 24 hours.

The ISWs report comes following claims of Russian progress earlier this week . The U.K. Defense Ministry said Saturday that paramilitary units from the Kremlin-controlled Wagner Group had seized most of eastern Bakhmut, with a river flowing through the city now marking the front line of the fighting. The assessment highlighted that Russias assault will be difficult to sustain without more significant personnel losses.

The mining city of Bakhmut is located in Ukraines eastern Donetsk province, one of four regions of Ukraine that Russian President Vladimir Putin illegally annexed last year. Russias military opened the campaign to take control of Bakhmut in August, and both sides have experienced staggering casualties. Ukrainian President Volodymyr Zelenskyy has vowed not to retreat .