A suicide car bombing in Iraq’s eastern Diyala province killed at least 80 people gathered at a marketplace to mark the end of the holy month of Ramadan.
Iraqi police officials said at least 50 people were also wounded in the attack in the town of Khan Beni Saad. Hospital officials confirmed the death tolls.
The officials spoke on condition of anonymity because they were not authorised to talk to the press.
The Islamic State group has claimed responsibility for the attacks, according to messages posted on Twitter. The claim could not be independently verified but it was posted by accounts commonly associated with the group.
Security has been ramped up in areas across Iraq since the start of Ramadan amid fears that the Sunni militant group would use the occasion to wage an assault on civilians to destabilise the Shiite-led government in Baghdad.
Parts of the predominantly-mixed Diyala province were captured by the Islamic State group last year. Iraqi forces and Kurdish fighters have since retaken those areas, but clashes between the militants and security forces continue.
In August last year, at least 64 people were killed in an attack on a Sunni mosque in the volatile province. The attack prompted Sunni lawmakers to pull out of sensitive talks last summer aimed at forming a new government after Prime Minister Haider al-Abadi was named premier-elect.
The Islamic State fighters had been trying to convince two prominent Sunni tribes in the area, the Oal-Waisi and al-Jabour, to join them, but that they have so far refused, provoking what many described as retaliatory attacks.
The Sunni militant group has been behind several similar large-scale attacks on civilians or military checkpoints as it seeks to expand its territory, which includes a third of Iraq and Syria.