If the parents of a minor unmarried child are separated without being divorced, the judge of the district court, upon application of either parent, may issue any civil process necessary to inquire into the custody of said minor unmarried child. The court may award the custody of said child to either party or both, in accordance with the best interests of the child, for such time and pursuant to such regulations as the case may require. The decision of the judge shall be guided by the rules prescribed in Section 2 of this act.