TOPSHOTS Shiite Muslim pilgrims walk in the Iraqi holy city of Najaf on November 26, 2015 where they take part in the Arbaeen religious festival which marks the 40th day after Ashura which commemorates the seventh century killing of Prophet Mohammed's grandson, Imam Hussein. Iraq has increased security around Shiite areas aiming at reducing the risk of suicide bomb attacks by the Islamic State (IS), an extremist Sunni group which controls parts of Iraq and considers Shiites heretics. AFP PHOTO / HAIDAR HAMDANI