Section 4. A civil action shall not be instituted against a public employer on a claim for damages under this chapter unless the claimant shall have first presented his claim in writing to the executive officer of such public employer within two years after the date upon which the cause of action arose, and such claim shall have been finally denied by such executive officer in writing and sent by certified or registered mail, or as otherwise provided by this section; provided, however, that a civil action against a public employer which relates to the sexual abuse of a minor, as provided in section 4C of chapter 260, shall be governed by section 4C1/2 of said chapter 260 and shall not require presentment of such claim pursuant to this section. The failure of the executive officer to deny such claim in writing within six months after the date upon which it is presented, or the failure to reach final arbitration, settlement or compromise of such claim according to the provisions of section five, shall be deemed a final denial of such claim. No civil action shall be brought more than three years after the date upon which such cause of action accrued; provided, however, that an action which relates to the sexual abuse of a minor, as defined in said section 4C of said chapter 260, shall be governed by said section 4C1/2 of said chapter 260. Disposition of any claim by the executive officer of a public employer shall not be competent evidence of liability or amount of damages.

Notwithstanding the provisions of the preceding paragraph, in the case of a city or town, presentment of a claim pursuant to this section shall be deemed sufficient if presented to any of the following: mayor, city manager, town manager, corporation counsel, city solicitor, town counsel, city clerk, town clerk, chairman of the board of selectmen, or executive secretary of the board of selectmen; provided, however, that in the case of the commonwealth, or any department, office, commission, committee, council, board, division, bureau, institution, agency or authority thereof, presentment of a claim pursuant to this section shall be deemed sufficient if presented to the attorney general.

The provisions of this section shall not apply to such claims as may be asserted by third-party complaint, cross claim, or counter-claim, or to small claims brought against housing authorities pursuant to sections twenty-one to twenty-five, inclusive, of chapter two hundred and eighteen; provided however, that no small claim shall be brought against a housing authority more than three years after the date upon which the cause of action arose.