in Bou Craa has led to charges of international law violations and divestment from several European states. Demographics The indigenous population of Western Sahara is usually known in Western media as Sahrawis, but they are also referred to in Morocco as "Southerners" or "Southern Berbers". They are Hassaniya-speaking or Berber-speaking tribes of Berber origin (97% of Y-DNA). Many of them have mixed Berber-Arab heritage, effectively continuations of the tribal groupings of Hassaniya-speaking and Zenaga-Berber speaking Moorish tribes extending south into Mauritania and north into Morocco as well as east into Algeria. The Sahrawis are traditionally nomadic Bedouins with a lifestyle very similar to that of the Tuareg Berbers from whom Sahrawis most likely have descended, and they can be found in all surrounding countries. War and conflict has led to major population displacement. As of July 2004, an estimated 267,405 people (excluding about 160,000 Moroccan military personnel) lived in the Moroccan-controlled parts of Western Sahara. Many people from parts of Morocco have come to live in the territory, and these latest arrivals are today thought to outnumber the indigenous Western Sahara Sahrawis. The precise size and composition of the population is subject to political controversy. The Polisario-controlled parts of Western Sahara are barren. This area has a sparse population, estimated to be approximately 30,000 in 2008. The population is primarily made up of nomads who engage in herding camels back and forth between the Tindouf area and Mauritania. The presence of land mines scattered throughout the territory by the Moroccan army makes this a dangerous way of life. Spanish census and MINURSO A 1974 Spanish census claimed there were some 74,000 Sahrawis in the area at the time (in addition to approximately 20,000 Spanish residents), but this number is likely to be on the low side, due to the difficulty in counting a nomad people, even if Sahrawis were by the mid-1970s mostly urbanized. Despite these possible inaccuracies, Morocco and the Polisario Front agreed on using the Spanish census as the basis for voter registration when striking a cease-fire agreement in the late 1980s, contingent on the holding of a referendum on independence or integration into Morocco. In December 1999, the United Nations' MINURSO mission announced that it had identified 86,425 eligible voters for the referendum that was supposed to be held under the 1991 Settlement plan and the 1997 Houston accords. By "eligible voter" the UN referred to any