(5) Investment of pension funds may also be made in the bonds of any municipal corporation or other public body of the state; and in any of the bonds or warrants, including local improvement bonds or warrants within the protection of the local improvement guaranty fund law, issued by any city or town which is a member of the system. Investment of pension funds may also be made in the bonds or other obligations of any other state or territory of the United States or of any political subdivision, agency or instrumentality of any such state, territory, or political subdivision thereof. Investment of pension funds may also be made in bonds or other obligations insured or guaranteed or which are covered by a repurchase agreement in whole or in part by the federal government or through any corporation, administrator, agency or instrumentality which is or hereafter may be created by the federal government.