Colonial efforts in Africa began in the 1920s, as civil war plagued Italian North Africa (Africa Settentrionale Italiana, or ASI) as the Arab population there refused to accept Italian colonial government. Mussolini sent Marshal Rodolfo Graziani to lead a punitive pacification campaign against the Arab nationalists. Omar Mukhtar led the Arab resistance movement. After a much-disputed truce on 3 January 1928, the Fascist policy in Libya increased in brutality. A barbed wire fence was built from the Mediterranean Sea to the oasis of Jaghbub to sever lines critical to the resistance. Soon afterwards, the colonial administration began the wholesale deportation of the people of the Jebel Akhdar to deny the rebels the support of the local population. The forced migration of more than 100,000 people ended in concentration camps in Suluq and Al-'Aghela where tens of thousands died in squalid conditions. It is estimated that the number of Libyans who died - killed either through combat or starvation and disease - was at least 80,000, and up to half of the Cyrenaican population. After Al-Mukhtar's capture on 15 September 1931 and his execution in Benghazi, the resistance petered out. Limited resistance to the Italian occupation crystallized around Sheik Idris, the Emir of Cyrenaica.