For the first time, the Kremlin has distributed its manual to soldiers providing instructions on how to dig and maintain mass graves, The Telegraph reports, as Russia continues to suffer mounting casualties in its war in Ukraine.

The 20-page textbook, titled "Civil Defense: Urgent burials of corpses in wartime," contains detailed diagrams showing mass graves with body bags stacked on top of each other, according to The Telegraph. The manual appears to be an updated version of one published in 2021, according to The Telegraph.

"Under normal working conditions, burying 100 dead in one mass grave will require 368.5 man hours," The Telegraph cites from the manual, which includes tables specifying the necessary equipment and manpower for mass burials.

The only documented use of mass graves for Russian soldiers thus far has been in occupied parts of eastern Ukraine's Donbas region, The Telegraph notes.

Ukrainian General Staff: Russian war losses in Ukraine reach 700,000

Russian forces have been attempting to capture key supply hubs in eastern Ukraine before winter weather conditions deteriorate, while 13,000 North Korean soldiers are expected to be deployed alongside Russian forces in its western Kursk Oblast, which Ukraine invaded in August.

The situation for Ukraine is further complicated by concerns about the upcoming US presidential election, with Republican candidate Donald Trump's skepticism about Ukraine's chances of defeating Russia raising fears about potential cuts to critical US military aid.