A Russian brigade commander, Colonel Medvechek, fighting in Ukraine has been killed by his own troops.

According to Western officials, Medvechek, commanding the 37th Motor Rifle Brigade, is believed to have been deliberately run down over anger at the number of casualties his unit was taking.

“The brigade commander was killed by his own troops, we believe, as a consequence of the scale of losses that have been taken by his brigade,” one official said. “We believe that he was run over by his own troops.”

And they added: “That just gives an insight into some of the challenges that Russian forces are having.”

Colonel Medvechek was reportedly targeted after Russian soldiers’ morale plummeted to an all-time low, with the official noting Moscow’s forces had unexpectedly “found themselves in a hornets’ nest and are suffering really badly” due to ongoing logistical and military issues.

The same official said that a lieutenant general commanding the 49th Combined Arms Army also recently died in the fighting. It makes him the seventh Russian general to be killed in combat since Russia’s war on Ukraine began – more than a third of those deployed at the start of the operation.

Nato has estimated that in four weeks of fighting, between 7,000 and 15,000 Russian troops have been killed. Though Russia’s latest death toll had the number of its soldiers killed at 1,351, according to Sergei Rudskoi, head of the Russian General Staff’s Main Operational Directorate, and 3,825 injured.

One Western official said that of the 115 to 120 battalion tactical groups the Russians had at the start of the war, 20 were no longer “combat effective”.

“After a month of operations to have somewhere in the region of a sixth, maybe even a fifth, of the forces being no longer effective, that is a pretty remarkable set of statistics,” they added.