Protests continue across Russia against the partial mobilization of military reservists that President Vladimir Putin announced last week. A US think tank suggests the mobilization may not greatly increase Russia's combat strength.

A Russian human rights group says more than 2,300 protesters have been detained in the last five days up until Sunday.

The governor of Irkutsk region said on Monday the top official of an enlistment office in Ust-Ilimsk was in critical condition after being wounded when a young man opened fire at the facility that day.

Independent Russian online media outlet Meduza reported that arsonists set fire to at least 10 military enlistment offices after the mobilization was announced.

The British defense ministry said in its intelligence update on Monday that the initial groups of men called up under Russia's partial mobilization have started arriving at military bases.

The intelligence update says many of the drafted troops will not have had any military experience for some years and not many are military trainers.

The update suggests many of the drafted troops will deploy to the front line with minimal relevant preparation, and that the recruits are likely to suffer a high attrition rate.

On Sunday, the US think tank Institute for the Study of War analyzed the protests and resistance to the involuntary mobilization, which it says reflect Putin's failures to prepare Russia for a major war.

Study of War notes Putin continued to call the invasion a "special military operation" rather than a war, and says how he has conveyed information about it in Russia failed to prepare his people for the involuntary mobilization.

The think tank says the mobilization will not affect the course of the conflict in 2022 and may not have a dramatic impact on Russia's ability to sustain its current level of effort into 2023.

It concludes that Putin is likely coming up against the hard limits of Russia's ability to fight a large-scale war.