A suicide bombing targeting a funeral gathering in northern Baghdad on Saturday killed at least 35 people and left 63 wounded, Iraqi police and hospital officials said.
The attack in the Shaab neighborhood occurred at lunchtime, said the officials, speaking on condition of anonymity because they were not authorized to brief the news media.
Islamic State claimed responsibility for the attack in a statement carried by the militant-linked Aamaq news agency. The claim could not be independently verified.
The attack comes as Iraqi security forces are preparing for an operation to retake the militant-held northern city of Mosul, the country's second-largest city, from Islamic State.
In the past, the extremists have increased insurgent attacks inside government-held territory far from the front lines after suffering territorial losses on the battlefield.
Iraq has seen several bombings in recent months, though most have had lower death tolls than Saturday's attack. In July, a massive car bomb in central Baghdad's popular shopping district of Karrada killed about 300 people and forced the resignation of the country's interior minister.