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.[3][4] 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.