State news agency Tass reported that the body of the soldier had been found on the site of the Novosibirsk Higher Military Command School (NVVK) in Siberia, according to the regional human-rights commissioner Nina Shalabayeva.

The local news outlet Sibkray.ru reported that the man was from Novosibirsk and, according to relatives, had died “as a result of violent actions.”

The name of the conscript and how long he was in the unit is unknown. Shalabayeva told the outlet that investigators were looking into the death and “are not giving more information.”

Shalabayeva said that, on Sunday, a 35-year-old volunteer from the Irkutsk region, southeastern Siberia, who was later named as Alexander Koltun, died in his sleep at the same site.

His mother, Elena Zausaeva, said he had died on the fourth day of his stay in the unit. She had been told on the phone that “he died from low-quality alcohol” and had been drinking there “for several days.”

“Now they are talking about heart failure,” she said, according to Zona Media, “but the fact is that my son never abused alcohol. He went to Ukraine absolutely consciously, voluntarily,” Irkutsk News reported that the cause of the death would not be disclosed.

Other deaths of mobilized troops have been emerging. Local news outlets NEFT and 72.ru said that the body of a man drafted in the Tyumen region, western Siberia, had been found on September 28 at a military assembly point.

Meanwhile, human-rights lawyer Pavel Chikov said on Monday that at least six newly drafted soldiers had died since the start of the mobilization drive in September.

Three died at an army training center in the Sverdlovsk region to the west of Russia, with federal lawmaker Maxim Ivanov telling news outlet EAN that one died from a heart attack and another committed suicide.

“The third one was discharged and sent home, where he died from cirrhosis of the liver,” Ivanov added.

The Sverdlovsk region’s human-rights commissioner Tatyana Merzlyakova confirmed the deaths of two of the soldiers, who were from the Kurgan region in southern Russia, but did not state the cause of death.

Another recruit, identified as Boris Shavaev from the republic of Kabardino-Balkaria, on the southern border with Georgia, died at a military base. Meanwhile, in the far-eastern city of Vladivostok, Sergei Fedoseenko, 39, died from a heart attack after being detained at a local enlistment office.

Putin’s mobilization of 300,000 reservists has been plagued by mistakes, such as people being wrongly called up to fight. Criticism of the botched draft on social media has added to pressure on the Russian leader as his invasion of Ukraine falters.

Newsweek has contacted Russia’s defense ministry and the NVVK for comment.