Two men shot at soldiers on a Russian military firing range near Ukraine on Saturday, killing 11 and wounding 15 before being slain themselves, the Russian Defence Ministry said.
The ministry said in a statement the shooting took place in the Belgorod region in southwestern Russia that borders Ukraine. It said the two men, from an unnamed ex-Soviet nation, fired on soldiers during target practice and were killed by return fire.
The ministry called the incident a terrorist attack.
The shooting comes amid a hasty mobilization ordered by President Vladimir Putin to beef up Russian forces in Ukraine — a move that triggered protests and caused hundreds of thousands to flee Russia.
Putin said on Friday that over 220,000 reservists already had been called up as part of an effort to recruit 300,000. He promised the mobilization would be wrapped up in two weeks.
Even though the Russian leader had declared that only people who had recently served in the military would be subject to the call-up, activists and rights groups have reported military conscription offices were rounding up people without any army experience — some of whom were also unfit for service for medical reasons.
Some of the freshly called-up reservists posted videos of them being forced to sleep on the floor or even outside, and given rusty weapons before being sent to the front lines.
Russian media reports said some of those who were mobilized were sent to combat without receiving proper training and were quickly killed.
Authorities have acknowledged the mobilization was often poorly organized and promised to improve the situation.