The Ministry of Internal Affairs of the USSR was the interior ministry of the Soviet Union from 1946 to 1991. The MVD was established as the successor to the NKVD during the reform of the People's Commissariats into the Ministries of the Soviet Union in 1946 as part of a broader restructuring of the government. The MVD did not include agencies concerned with secret policing unlike the NKVD, with the function being assigned to the Ministry of State Security (MGB), which had been established during the Second World War. The MVD and MGB were briefly merged into a single ministry from March 1953 until the MGB was split off as the Committee for State Security (KGB) in March 1954.