The emergency occurred at the training ground near Belogorsk during routine night shooting. "The serviceman released a line from the submachine gun in the direction of the group waiting to enter the firing line," the Russian Defense Ministry said in a statement..

The officer and two servicemen died from wounds on the spot, two more soldiers were taken to the hospital. The shooter disappeared from the territory of the test site, with him an automatic and several horns with cartridges.

"The command, together with law enforcement agencies, took measures to search for him and detain him," the ministry said..

As probable causes of the incident, all versions are considered, including a nervous breakdown of a serviceman, added to the ministry.

The Investigative Committee opened a criminal case under the article "Murder". Defense Minister Sergei Shoigu sent a commission to the Amur region, headed by the chief of the main headquarters of the Land Force.

The head of Belogorsk, Stanislav Melyukov, reported on the incident to the governor of the Amur Region, Alexander Kozlov, who instructed to strengthen the protection of schools, boiler houses, city hospitals and administrative buildings "in order to avoid situations involving possible hostage-taking".