Aformer Wagner mercenary has admitted to killing and torturing dozens of Ukrainian prisoners of war, in one of the most detailed first-person accounts of atrocities committed by Russian forces in Ukraine. Alexey Savichev, 49, a former Russian convict recruited by Wagner last September, told the Guardian in a telephone interview that he participated in summary executions of Ukrainian prisoners of war during his six months of fighting in eastern Ukraine. “We were told not to take any prisoners, and just shoot them on the spot,” he said. In one instance, while fighting near the eastern Ukrainian city of Soledar last autumn, Savichev said he participated in the killings of 20 Ukrainian soldiers who were surrounded. “We sprayed them with our bullets,” he said. “It is war and I do not regret a single thing I did there. If I could, I would go back.” Savichev said that in another episode, with other Wagner fighters he had killed “several dozen” injured Ukrainian PoWs by “tossing grenades” into the ditch where they were held near the city Bakhmut in January. “We would torture soldiers too, there weren’t any rules,” he said. Savichev’s account was first published on Monday by the Gulagu.net rights group in an hour an 17 minute-long video, where he appeared alongside another former Wagner fighter, identified as Azamat Uldarov, who also said he had killed civilians, including children, during the battle for Bakhmut. Uldarov said his fellow mercenaries in one instance killed a group of people who had taken shelter in the basement of a nine-floor block of flats in Bakhmut, including a young girl. “She was screaming, she was a little kid, she was five or six and I shot her, a kill shot. I wasn’t allowed to let anyone out, you understand?” Uldarov told Vladimir Osechkin, the head of the Gulagu.net rights group. He could not be reached for comment. The Guardian cannot independently verify either man’s harrowing claim but has seen Russian penal documents showing that Savichev, who was a convicted murderer, was released from a prison in Voronezh, a city in south-west Russia, on a presidential pardon on 12 September. Wagner has recruited tens of thousands of inmates, including convicted murderers, to fight in eastern Ukraine. They were offered freedom if they survived a near-suicidal six-month stint, one Savichev completed on 12 March. Savichev also provided the Guardian with photographs of two medals that he said he received for the battle of Soledar, a town in eastern Ukraine that Wagner troops captured in early January. His testimony appears to contribute towards a mounting body of evidence that sheds light on the war crimes committed by Russian soliders in Ukraine. Earlier this month, two videos emerged showing Russian soldiers apparently beheading Ukrainian prisoners of war. Ukraine’s president, Volodymyr Zelenskiy, said the world could not ignore the “evil” footage, which has not been verified by the Guardian. “How easily these beasts kill. We are not going to forget anything. Neither are we going to forgive the murderers,” he said. Responding to the interview published by Gulagu Net, Zelensky’s chief of staff, Andriy Yermak, said those responsible should be punished. “Confession is not enough. There must be a punishment. Tough and fair. And it will definitely be,” Yermak wrote on Twitter. Since the start of the war, a number of Russian soldiers, including one former Wagner convict, have fled abroad and described witnessing Russian war crimes, but Savichev’s testimony is a rare account of a former Wagner soldier still in Russia. Savichev said he has been on the run since giving his first interview on Monday and had received “multiple” threats. Yevgeny Prigozhin, head of Wagner, said the account of the two former Wagner soldiers was a “flagrant lie” and that Wagner fighters “have never touched and do not touch” children. Savichev said he feared he would face the same consequence as Yevgeny Nuzhin, a convicted murderer recruited by Wagner who surrendered to Ukrainian forces but was later handed over to Russia and executed. “I was with Wagner, and know what they can do to those who speak out,” Savichev said. “I understand I could die soon. I just don’t want my death to be violent.” He said he had witnessed multiple summary killings of other Wagner fighters accused by their commanders of disobeying orders or of breaking the “code of conduct”, including regarding the consumption of alcohol. Savichev said he joined Wagner after Prigozhin visited his IK-12 colony in Voronezh last September. “Prigozhin came to our prison and said that he was looking for killers. He said the regular army was full of wussies who couldn’t get the job done.” He said he was accepted into Wagner despite his HIV diagnosis – Russia’s regular army does not permit soldiers with serious diseases to join its ranks. “They don’t care if you have HIV or hepatitis, as long as you can kill,” he said. According to Savichev’s account, just over 100 prisoners from IK-12 in Voronezh signed up to fight with Wagner. After a two-week training course, he was sent to the frontlines, fighting first in Soledar and, after the town’s capture, in Bakhmut. He said he was placed in small units of four that were used as “storming troops”, who were ordered to launch extremely dangerous assaults on Ukraine’s positions. He estimated that of the 100 prisoners recruited from his prison, only 21 returned alive. According to western estimates, Wagner has suffered more than 30,000 casualties, mostly former convicts, since Moscow’s invasion of Ukraine last February. “We were basically just meat for our commanders, I still don’t know how I survived,” Savichev said. “No one gave a shit about us.”