The Russian Defense Ministry said the attack in the Belgorod region, which borders Ukraine, occurred as a weapons education session.
Russia introduced what it calls a special army operation in Ukraine in late February. Last month, Russian President Vladimir Putin ordered the mobilization of 300,000 Russians who had in the past completed their mandatory military service.
“On October 15, two citizens of a CIS country committed a terrorist act in a flat of the Western Military District in the Belgorod region,” the ministry was quoted as saying by state news agencies.
“As a result, another 11 people were fatally injured. Another 15 people suffered injuries of varying severity and were taken to medical facilities. “
The two attackers “died in retaliation,” the ministry added.
The CIS, or Commonwealth of Independent States, was formed among the republics that were part of the Soviet Union.
More than 200,000 more people have enlisted in the Russian armed forces since the announcement of partial mobilization on September 21.
The proposed announcement sparked protests and attacks on recruitment offices.
Ukrainian President Volodymyr Zelensky said Saturday that his troops were facing a “very difficult” scenario near the eastern city of Bakhmut, which has been under attack by the Russian military for weeks.
Ukraine is regaining territories in the east and south, occupied through Russia for months, but faces a complicated challenge in some regions.
“A very serious situation persists in the Donetsk and Luhansk regions,” Zelensky said, referring to two regions that Russia says it has annexed.
“The ultimate deception is close to Bakhmut, as in the last days. We still hold our positions,” he said.
Russian troops have been shelling Bakhmut, a wine and salt city once populated by 70,000 people, for weeks in hopes of seizing the city.
Zelensky said Russia’s overall losses now stood at 65,000.
One soldier, who had just returned from the front, told AFP they had been fighting for four days of disruption.
“Of the thirteen boys in my group, we lost two soldiers and five were evacuated,” said the 50-year-old soldier, “Poliak,” of the 93rd Brigade.
“For days I didn’t sleep, I didn’t eat, I didn’t drink coffee,” he added.
France said it would have up to 2,000 Ukrainian troops on its soil.
Armed Forces Minister Sebastien Lecornu said France would also supply Ukraine with Crotale air defense systems “to allow it to protect its skies. “
Saturday’s attack on Belgorod soil is the latest in a series of incidents that have affected the Russian region.
Earlier on Saturday, Vyacheslav Gladkov, governor of Belgorod, said an oil depot was burning after being bombed. He posted a photo of flames and plumes of black smoke emerging over a building.
Last week, Russia complained about a buildup of artillery and missile movements on its border territory with Ukraine.
And on Friday, the government said a Ukrainian strike set fire to a power plant in the regional capital, also known as Belgorod, causing power outages.
This came a day after a rocket pierced the most sensitive floor of an apartment building in the city of Belgorod, causing no injuries.
An ammunition depot in the domain was also destroyed on Thursday.
Earlier in the week, Russian officials said Ukrainian movements had reduced strength in the city of Shebekino in the same region. A 74-year-old man was killed and several others were injured in the city.