Combat crews of the air defense missile systems S-400 Triumf, provided for an air defense regiment of the Central Military District in the Urals, have entered duty in the Sverdlovsk Region, the military district’s press-service said in a news release on Friday.

"In a special ceremony the order to enter combat duty was read out to the personnel. S-400 Triumf combat crews alerted the air defense systems and began to perform the task of guarding the airspace in the Urals air defense zone of responsibility," the news release runs.