16 anti-aircraft forces of 23 mm were formed for the first surface-to-air missiles to provide protection from hostile air attacks. Fifteenth: Form 15 mixed batteries consisting of Shilka and Strela 1 M for armored and mechanized field formations to confront the very low air threat from the ground forces. Sixteenth: A number of air defense commands for the corps, armored divisions, mechanized and infantry were formed to secure command and control of the field air defense units operating within the corps and divisions, as follows: