In July 1941, formations of the NKVD were providing security for government installations, railway lines, and industrial centres. Railway security forces totalled 62,100, comprising nine divisions and five brigades securing 1,700 sites. Operational forces, the direct forerunners of the Internal Troops, included 11 regiments stationed in the western military districts, seven regiments and three battalions in the internal districts, and the F. E. Dzerzhinsky Independent Special Designation Division in Moscow (transferred from the OGPU in 1934). In October 1940, a specialised NKVD force had also been formed to assist with local air defence for important areas. By June 1941 this new Main Directorate for Local Antiaircraft Defence had three regiments, including in Moscow, and four battalions, all engineer-anti-chemical units. Another division and five brigades totalling just under 30,000 men were in the process of formation.