Any peace officer or any person employed as watchman, guard, or in a supervisory capacity on premises connected with or used for national defense activities and posted with a sign reading “No Entry Without Permission” may stop any person found on any premises to which entry without permission is forbidden, and may detain him for the purpose of demanding, and may demand, of him his name, address and business in such place. If said peace officer or employee has reason to believe from the answers of the person so interrogated that such person has no right to be in such place, said peace officer may arrest such person without a warrant on the charge of unlawful entry; and said employee shall forth-with turn such person over to a peace officer who may arrest him without a warrant on the charge of unlawful entry.