The mostly-Shia victims were gathered to mark the end of the Islamic holy month of Ramadan, which ended on Friday for Iraqi Shias and a day earlier for Iraqi Sunni Muslims.

Police said a small truck detonated in a crowded marketplace in the town of Khan Beni Saad on Friday night in what quickly turned celebrations into a scene of horror, with body parts scattered across the market. At least 170 people were injured in the attack, police officials said, speaking anonymously because they are not authorised to brief the media.

The Islamic State group claimed responsibility for the attack in a statement posted on Twitter accounts associated with the militant group.

 Security forces were out in full force across Diyala on Saturday, with dozens of new checkpoints and security protocols immediately implemented in the wake of Friday’s attack.

“This horrible carnage is truly outside all boundaries of civilised behaviour,” Jan Kubis, the special representative of the United Nations mission in Iraq, said Saturday.”

The Sunni militant group has been behind several similar large-scale attacks on civilians or military checkpoints as it seeks to expand its territory. The group currently controls about a third of Iraq and Syria in a self-declared caliphate.