Since a United Nations-sponsored ceasefire agreement in 1991, about two thirds of the territory is administered by Morocco, including the majority of the coast. This territory is separated by fortified berm from the Polisario Front-controlled remainder, which has a population of about 30,000. Polisario's army is considered incapable of covering the vast one-third of Western Sahara, east of the Moroccan berm. Moreover, most of Polisario's army is thought to be concentrated in the Tinduf area inside Algeria, protected by Algeria from the long arm of Morocco's artillery and air force.