Washington: The Islamic State jihadist group on Wednesday claimed the deadly bombing at a market in a Shia Muslim district of Baghdad, US terrorism-tracking website SITE reported.
The suicide bombing killed close to 70 people and wounded 100, the ultra-hardline Sunni group said in an online statement, according to SITE.
Iraqi officials said 64 people died and at least 87 others were wounded in the rush-hour bombing in Sadr City - the biggest attack in the Iraqi capital in months.
Many of the victims included women and children, Iraqi police and medical sources said. Several of the injured were said to be in critical condition.
In February, Iraqi security forces began building a wall around Baghdad in an attempt to halt a spike in attacks. These killed 1,885 people in the first four months of this year, according to the UN.
An international military coalition's fight against the IS has stoked a long-running sectarian conflict in Iraq, mostly between Sunnis and Shias, which emerged after the US-led invasion in 2003.
The IS, which considers Shias heretics, claimed a twin suicide bombing in Sadr City in February that killed 70 people and has also taken credit for recent attacks across the country.