Gunmen shot dead 11 people at a Russian military training ground on Saturday, the defense ministry said, in the latest blow to President Vladimir Putin's forces since the invasion of Ukraine.

RIA news agency cited the ministry as saying 15 other people were wounded in the shooting on Saturday in the southwestern Belgorod region that borders Ukraine when two men gunned down a group who had volunteered to take part in the war.

It said the two assailants — nationals from an unspecified former Soviet republic — had also been shot dead. Some Russian independent media outlets reported that the number of casualties was higher than the official figures.