Whenever the Minister is satisfied that it is necessary in the public interest to do so, he may, after consultation with the board and any other Minister which in his opinion has any interest therein, and with the concurrence of the Minister of Finance, make such arrangements as he may deem expedient to provide for the training in a particular trade or occupation of persons who are not apprentices or minors, and he may for that purpose by notice in the Gazette issue such directives as he may deem necessary for such training: Provided that the Minister may after consultation with the board provide, in terms of the aforegoing provisions of this section, for the training of persons who are minors but who have completed a first period of training or service in terms of the provisions of the Defence Act, 1957 (Act No. 44 of 1957), or section 34A(11) of the Police Act, 1958 (Act No. 7 of 1958).