(a) The treasurer of any municipality or county or board of trustees of any independent school district may invest any surplus funds in his hands, or any special funds held or being accumulated for any special purpose, or any funds on hand not required for the operation of the municipality, county, or school district for the current fiscal year. He may invest such funds in war bonds or other valid obligations of the United States government, repayable at face value or better, when such investment is authorized by the mayor and general council, county commission, judge of the probate court, board of trustees, or other authority in charge of the affairs of said municipality, county, or independent school district, provided funds accumulated for any special purpose shall be invested only in securities whose maturity date is prior to the date when such funds shall be needed for said special purposes or which are redeemable prior thereto without penalty or loss of principal.

(b) Any bonds or other securities purchased or held pursuant to subsection (a) of this Code section shall be held subject to the same conditions as those attached to the funds from which same were purchased.