Shiite Muslim pilgrims gather outside the Imam Hussein shrine on the last day of the Arbaeen religious festival on November 21, 2016, in the holy Iraqi city of Karbala, 50 miles (80 kilometres) south of Baghdad. The Arbaeen religious festival marks the 40th day after Ashura which commemorates the seventh century killing of Prophet Mohammed's grandson, Imam Hussein. / AFP PHOTO / Mohammed SAWAF

A suicide truck bomb killed about 100 people, most of them Iranian Shia pilgrims, at a petrol station in the city of Hilla 100 km south of Baghdad on Thursday, police and medical sources said.
Islamic State, which considers all Shias to be apostates, claimed responsibility the attack in an online statement.
The group is also fighting off a U.S.-backed offensive on its stronghold Mosul, in northern Iraq, in which Iranian-trained Shia militias are taking part.
Medical sources said the pilgrims were en route back to Iran from the Iraqi Shia holy city of Kerbala, where they had commemorated Arbaeen, the 40th day of mourning for the killing of Imam Hussein, a grandson of the Prophet Muhammad, in the 7th century CE.
The gas station has a restaurant in its premises that is popular with travellers. Five pilgrim buses were torched by the force of the blast from the explosives-laden truck, a police official …