A picture taken on July 9, 2015, shows the Algerian town of Guerara in the M'zab valley after clashes erupted between its Berber and Arab communities. Algeria is mobilising the army after 22 people were killed in the worst ethnic clashes between Berbers and Arabs in years, as more details emerged of the violence. AFP PHOTO / FAROUK BATICHE        (Photo credit should read FAROUK BATICHE/AFP/Getty Images)