This was stated by terrorist and formed so-called 'defense minister' of self-styled "Donetsk people's republic" Igor Girkin (Strelkov) on his page in VKontakte, Censor.NET reports.
He is citing a former fighter from Wagner private military company who had fought in the Donbas and Syria as saying that over the past week, three people were killed and many more wounded from his former detachment.
"Another my former subordinate is now in hospital in Odintsovo, wounded in Syria within Wagner's group. He's not alone - several people arrive every week," Girkin wrote.
"From a third source I know that estimated losses of "official military" over the past two weeks reached up to 20 people; private military companies lost, respectively, three times more. And those are minimum estimates.
"Such losses of regular military and mercenaries (who are contract soldiers in fact) are caused by rapid escalation of fighting against ISIS in Deir ez-Zor and Mayadin, where Russian private military companies (by 90% comprising Slavic people) are used as assault groups," Girkin wrote.