A twin suicide bombing claimed by Islamic State killed 70 people in a Shi'ite district of Baghdad on Sunday in the deadliest attack inside the capital this year, as militants launched an assault on its western outskirts.
Police sources said the suicide bombers were riding motorcycles and blew themselves up in a crowded mobile phone market in Sadr City, wounding more than 100 people in addition to the dead.
A Reuters witness saw pools of blood on the ground with slippers, shoes and mobile phones at the site of the blasts, which was sealed off to prevent further attacks.
In a statement circulated online, Islamic State said it was responsible for the blasts: "Our swords will not cease to cut off the heads of the rejectionist polytheists, wherever they are," it said, using derogatory terms for Shi'ite Muslims.
Iraqi forces backed by airstrikes from a U.S.-led coalition have driven Islamic State back in the western Anbar province recently and are preparing for an offensive to retake the northern city of Mosul.
But the militants are still able to strike outside territory they control, often targeting members of Iraq's Shi'ite majority, most recently on Thursday when two Islamic State suicide bombers killed 15 people at a mosque in the capital.
Prime Minister Haider al-Abadi said the attacks were in response to Islamic State's recent defeats: "This gang targeted civilians after it lost the initiative and its dregs fled the battlefield before our proud fighters," he said on his official Facebook page.