Russia launched a surprise invasion of the Kharkiv region from its Belgorod region in May, while its forces suffered high casualties attempting to repel Ukraine’s ongoing incursion into the Kursk region.

September was also the fifth consecutive month that Russian casualties averaged more than 1,000 soldiers per day.

Analysts said that the high casualty rate was linked to Russian mass infantry tactics, often involving “meat wave” assaults where large numbers of troops are sent to storm Ukrainian defensive positions.

“I expect Russia to continue to grind forward, probing for weakness. Very grim. We can’t expect a Russia pause over the winter,” said John Foreman, Britain’s former defence attache in Moscow.