Unarmed Russian soldiers run into Ukrainian fire for the sole purpose of digging trenches or carrying ammunition. Those who refuse could be killed or imprisoned, report says.

• Russian forces are in a prolonged battle with Ukrainian soldiers to capture Bakhmut.
• They've slowly made advances in part by using anti-retreat units, Ukrainian commanders told NYT.

Unarmed men with the sole purpose of digging trenches or carrying ammunition are being sent toward Ukrainian fire as part of Russia's unrelenting efforts to capture Bakhmut, according to Ukrainian soldiers who spoke to The New York Times.

Russia has made incremental process in Bakhmut since it waged a battle in the eastern Donetsk region more than seven months ago but at a deadly cost: A NATO official estimated five Russian soldiers died for every Ukrainian soldier killed.

A media officer for Ukraine's Third Assault Brigade, which has spent the past three months in Bakhmut, told the newspaper his unit surmised some of the fighters might be on drugs, bewildered that the men would so willingly move toward their death. Ukrainians have previously speculated that Russian soldiers might be taking drugs, though there is no evidence this is the case.

But the men also may not have much of a choice.

Russia is using what Ukrainian commanders described to the Times as anti-retreat units in which soldiers, some of them unarmed, push forward enemy fire.

Yaroslav, a Ukrainian soldier who leads a drone unit, told the Times that men can face the possibility of execution or imprisonment if they turn back. (Ukrainian soldiers interviewed by the Times were only identified by their first name or military nicknames.)

In drone footage shown to the newspaper, a lone unarmed Russian soldier could be seen briefly looking back before he continued to move toward incoming weapons fire.

"Do you see? He's not carrying a weapon," Yaroslav told the Times. "He's a digger."

Ukrainian commanders have also heard orders against desertion in intercepted phone calls or seen them written on a document found in the pocket of a dead soldier, the Times reported.

Other reported Russian strategies included sending prisoners recruited by the Wagner Group, Yevgeny Prigozhin's paramilitary organization, to the frontlines in order to draw fire and reveal a Ukrainian unit's position.

"I'll be honest. It's genius. Cruel, immoral, but effective tactics. It worked out. And it's still working in Bakhmut," one soldier told BBC.

Yaroslav told the Times most of the Russian soldiers in Bakhmut have little training but are effective at crawling and hiding underground.

"They will just crawl," he told the Times. "Even when there are bullets flying a meter over their heads, they will just crawl."