It was put into service with the 15th Anti-Aircraft Missile Brigade.
Belarusian Defense Minister Viktor Khrenin visited an anti-aircraft missile unit, where the S-400 SAM system was put into service. This was reported by the Ministry of Defense of Belarus. During the visit, Khrenin “assessed the unit’s preparation for combat duty, including the personnel’s ability to perform assigned tasks, as well as the readiness of weapons and military equipment.”
The photos published by the Ministry of Defense (among other things) show Colonel Andrei Dolbik, the commander of the 15th Anti-Aircraft Missile Brigade of the Belarusian Armed Forces (military unit 30151).
We can also note that in the video of VoyenTV about the arrival of the S-400 SAM system to Belarus, a soldier of the 15th Anti-Aircraft Missile Brigade reported to Colonel Lukyanovich, the commander of the Air Force and Air Defense Forces. Thus, there are reasons to state that the S-400 SAM system was put into service with the 15th Anti-Aircraft Missile Brigade. In January 2023, the 15th Brigade also received a battery set of Tor-M2K systems.
Location of the S-400 SAM system on the territory of Belarus Belarusian Hajun
Analysis of photos/videos published by the Ministry of Defense of Belarus shows that today Khrenin visited the positions of the 6th Anti-Aircraft Missile Division of the 15th Anti-Aircraft Missile Brigade, located near Dubrova village (Smaliavichy district, Minsk region). Therefore, the 6th Division of the 15th Brigade received a set of the S-400 SAM system from Russia.