According to a statement from the Senior State Attorney's Office, from October 3, 1991 until July 2, 1992, as members of the Yugoslav People's Army (JNA) active and reserve forces, the suspects treated civilians and prisoners of war from the Dubrovnik area contrary to provisions of international law.
The names of the suspects were not given.
The statement said that the Croatian Chief Public Prosecutor had been notified of the decision.
Montenegrin prosecutors decided to investigate the case after recently receiving all relevant information from the Croatian Chief Public Prosecutor's Office.
Montenegrin media said on Sunday that the request for investigation was prompted by the arrival of UN war crimes prosecutor Carla del Ponte, who is due in Podgorica on Monday.
Media were told by prosecutors that all the persons to be investigated were in Montenegro and within reach of the authorities.