They are the nameless ones. The faceless ones. Called the “men in green,” they are a group of hundreds, if not thousands, of Russians fighting in Ukraine with neither identifying insignia nor official documents — soldiers in everything but name. Instead, they’re called “volunteers.” They’re called “vacationers.” They’re “blood brothers,” as rebel leader Alexander Zakharchenko described the Russians crossing the border to fight alongside him.

But such anonymity, which helps Moscow pretend that no Russian soldier fights in Ukraine, comes at a high cost. Rights groups, activists and local journalists now allege that Russia, already burdened with a dark history of soldier abuse, has suppressed the truth of its own killed soldiers, obfuscated details of their demise and buried some of the dead in unmarked graves to hide their role in Ukraine. And Russia’s response if its soldiers are caught: They’re wanderers who “accidentally” crossed the border.

Valentina Melnikova, who leads the Soldiers’ Mothers Committee, told the Daily Beast she was “personally humiliated as a citizen of the Russian Federation by our commander-in-chief’s pure, direct crime.” She said Russian President Vladimir Putin is “violating not only international laws, not only the Geneva Convention, [he] also is breaking Russian Federation law about defense. And as for the [Russian airborne commander], we should be too disgusted to even mention his name. He forces his servicemen to fight in a foreign state, Ukraine, illegally, while mothers receive coffins with their sons, anonymously.”

Another rights activist said he got a call from a Russian mother. The woman said her son’s remains were dropped off at her house last week. The accompanying documents said he had died of wounds — but there was no mention of where he died. “She called other soldiers who served with her son,” Sergei Krivenko, of Russia’s Presidential Human Rights Council, told USA Today. “These aren’t just civilians, but people who are following [military] orders. That is why we asked that these deaths be investigated.”

That battle in which the woman’s son died may have occurred on Aug. 13. It was an eastern Ukraine skirmish that Reuters reported claimed the lives of more than 100 Russian soldiers. Despite the high death count, news of the fight broke Thursday — more than two weeks later.

The Russian Human Rights Council told Reuters the bodies were found without documentation proving they had been in Ukraine and with death certificates saying they had died elsewhere. “The soldiers serving on contract are given an order, and the columns go across Russia and they stop at a camp, as though part of a training exercise, on the border with Ukraine,” a council spokesman told the news agency. “They take off all the [identification] numbers or blotch them out.”

Other soldiers, however, possibly had more than just a number obscured. Numerous reporters, from the BBC to Reuters to local Russian journalists, have investigated what appear to be freshly dug, unmarked graves possibly holding the bodies of several Russian paratroopers who were killed last week in Ukraine. Reuters reported that all online accounts of the men who were buried there have been removed from the Internet, as have photos of the soldiers that their families placed on their graves. When Russian journalists traveled there, the BBC reported that men told them they would “never be found” unless they left.

“The [Russian] government is disavowing soldiers who are” in Ukraine, soldier activist Valentina Melnikova told USA Today. She estimated that as many as 15,000 Russian soldiers have crossed into Ukraine.

The Post’s Karoun Demirjian reports that one mother fainted when she got a call from a neighbor — not the army — who had seen a picture of her son in captivity in Ukraine. On Thursday, Demirjian said, the families of paratroopers went to a cramped office hoping to meet a representative of the military to get some information. They waited about two hours before getting a meeting with officers, which lasted about five minutes and was inconclusive. Later, some of them received calls from their sons in detention in Kiev, she reported.

Russia’s unwillingness to report soldier deaths reflects a dark precedent for its military, which has often peddled misinformation and trafficked in ambiguity. Only at the very end of the Soviet Union’s war in Afghanistan did it specify that more than 13,000 had been killed, according to a 1988 New York Times report, with an official confessing that losses had been “quite heavy.” Parents, unaware of what had happened to their sons, had ventured into the region in search of them.

The war in Chechnya wasn’t much better. “I would trust maybe only a quarter of what is said about Chechnya,” one soldier told the Moscow Times in 1999. “One other soldier was killed from my unit. I called his mother, and she didn’t know.” Another soldier added: “I’m positive that the number of victims is being hidden because the military authorities don’t want panic in Russia and negative feelings about the war.”

The lot of the Russian soldier can be a sad one. Bullying and hazing, called dedovshchina, can be so severe that many soldiers are driven to suicide. “Such abuse is common throughout Russia’s armed forces,” the Chicago Tribune once said. “Its teenage victims frequently end up with serious injuries. An alarming number are killed or driven to commit suicide. Almost always, the mistreatment is ignored or covered up.”

In 2002 alone, hazing-related beatings killed more than 500 men, Russian journalist Anna Politkovskaya, who was later murdered, told the BBC. “Officers are united in hatred of soldiers’ parents because every so often, when the circumstances are just too disgraceful, outraged mothers protest at the murder of their sons and demand retribution.”

Now, as more Russian “volunteers” flood across Ukraine’s borders under uncertain circumstances, that same anger appears to be growing in some Russian mothers. “Their connection [with soldiers] is lost,” one Soldiers’ Mothers official told USA Today. “They are afraid, they fear tragedy. Wives, mothers are coming to us.”