 At around 1 : 00 am on 22 June 1941 , the Soviet military districts in the border area were alerted by NKO Directive No. 1 , which was issued late on night of 21 June . It called on them to " bring all forces to combat readiness , " but to " avoid provocative actions of any kind . " It took up to 2 hours for several of the units subordinate to the Fronts to receive the order of the directive , and the majority did not receive it before the invasion commenced . 
