 Also participating in the program are the Volunteer Firemen's Corps, the Guatemalan Army and demobilized members of the Guatemalan National Revolutionary Union.Operations in Guatemala are somewhat unusual within the OAS program, as the primary threat comes from the approximately 8,000 unexploded devices, including mortar and artillery shells, aerial bombs and hand grenades, which are scattered throughout Guatemalan territory.The clearance process requires extensive cooperation among the three operational components, as well as a concerted effort to communicate with the population of affected zones in order to locate and destroy hazardous items.