An officer may break and enter any premises or vehicle when necessary to the execution of the warrant if:
(1) The officer has previously announced his identity and purpose as required by G.S. 15A‑249 and reasonably believes either that admittance is being denied or unreasonably delayed or that the premises or vehicle is unoccupied; or
(2) The officer has probable cause to believe that the giving of notice would endanger the life or safety of any person. (1973, c. 1286, s. 1.)