The Kremlin-affiliated Wagner paramilitary group suffered 138 casualties and injuries in the last 24 hours, Ukrainian military official Brig.-Gen. Oleksiy Gromov said in a Thursday briefing.
Gromov, the deputy head of the Chief Operative Management of the General Staff of the Ukrainian Armed Forces, said that close to 40 members of the mercenary organization were killed in fighting in Bakhmut, a strategically important town in Ukraine's eastern Donetsk region.
Ukraine is also "studying" Russia's progress on "reconstructing the so-called Wagner line," Gromov added. Ukraine's Main Intelligence Directorate (GUR) reported last month that over 8,000 Wagner mercenaries were deployed on the frontlines for Russia.
The Wagner group had been accused by the West of committing human rights atrocities in the wartorn areas of eastern Ukraine. Intelligence reports have long stated that Russia is working to recruit prisoners through mercenary groups like Wagner to shore up its heavy losses in the Ukraine war.
The news of losses among Wagner mercenaries comes a day after Moscow ordered troops to withdraw from near the strategic southern Ukrainian city of Kherson. According to a top US general, Russia has suffered more than 100,000 killed or wounded since invading its neighbor in February.
Ukraine, UK express caution over Russian withdrawal in Kherson
Ukrainian President Volodymyr Zelensky spoke on Thursday with UK Prime Minister Rishi Sunak on Russia's evacuation of Kherson and the Dnipro River, with the two leaders agreeing that the Russian withdrawal represents "strong progress" for Ukrainian forces.
However, during a phone call between the two leaders, both also said it was right to express caution about the withdrawal "until the Ukrainian flag was raised over the city," a spokesperson for Sunak said.
"The prime minister praised the bravery of the Ukrainian armed forces and reiterated the UK's unwavering military, economic and political support," the spokesperson added.
Reuters contributed to this report.