The Free Zone or Liberated Territories is a term used by the Polisario Front government of the Sahrawi Arab Democratic Republic, a partially recognized sovereign state in the western Maghreb, to describe the part of Western Sahara that lies to the east of a border wall flanked by a minefield, often referred as the Berm, and to the west and north of the borders with Algeria and Mauritania, respectively. It is controlled by the Sahrawi Arab Democratic Republic, as opposed to the area to the west of the Berm, which is controlled by Morocco as part of its Southern Provinces. Both states claim the entirety of Western Sahara as their territory. The zone was consolidated as a Polisario-held zone in a 1991 cease-fire between the Polisario Front and Morocco, which had been agreed upon together as part of the Settlement Plan. Morocco controls the areas west of the Berm, including most of the territory's population. The cease-fire is overseen by the United Nations' MINURSO forces, charged with peacekeeping in the area and the organization of a referendum on independence. Status and military agreement The status of Western Sahara is hotly disputed between Polisario and Morocco, and this includes the names used to refer to areas under the control of the different sides. Morocco routinely refers to the Polisario-held region as a "buffer zone", or "buffer strip", and claims that Polisario forces are not allowed entry, and that both military activities and civilian construction in this area constitute violations of their cease-fire agreement. The Polisario Front, on the other hand, claims this does not correspond to the provisions of the agreement regulating the territory's status, which Morocco signed in 1991, and regards the "buffer strip" as only a slim portion of the entire territory. This zone serves as a division-of-forces no man's land. Areas outside this zone are open to activity by the side that controls them, provided they adhere to some restrictions on military movements. Similarly, Polisario call the areas a "liberated territory" or the "free zone", but this is not an official designation. The UN calls it simply "east of the Berm", and refers to territories under Moroccan control as "west of the Berm", thus not giving sanction to the claims of either party. According to the Settlement Plan, the movement of Polisario fighters is restricted similarly to how Moroccan forces face restrictions on their side of the Berm.