Every city and town may invest any portion of the moneys in its inactive funds or in other funds in excess of current needs in:
(1) United States bonds;
(2) United States certificates of indebtedness;
(3) Bonds or warrants of this state;
(4) General obligation or utility revenue bonds or warrants of its own or of any other city or town in the state;
(5) Its own bonds or warrants of a local improvement district which are within the protection of the local improvement guaranty fund law; and
(6) In any other investments authorized by law for any other taxing districts.