274.—In any area specified in a manœuvres (authorisation) order or in the vicinity of any place used for artillery, rifle, bombing or other army, naval or air practices, the officer in command of the portion of the Defence Forces engaged in the manœuvres or in such practices may temporarily stop all traffic by land or water in that area or in the vicinity of that place so far as in his opinion may be necessary for the security of life and the proper conduct of the manœuvres or such practices.