BAGHDAD — Anger swelled in volatile Dyala province on Saturday as the death toll from an Islamic State attack on a crowded market the day before rose to 115 people. It was one of the deadliest single attacks in the country in the past decade.
The mostly Shi’ite victims were gathered to mark the end of the Islamic holy month of Ramadan, which ended Friday for Iraqi Shi’ites 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 Friday night in what quickly turned celebrations into a scene of horror, with remains scattered across the market. At least 170 people were injured in the attack, police officials said, speaking anonymously because they are not authorized to brief the media.
Men quickly emptied boxes of tomatoes to use them for carrying the bodies of young children, witnesses said, while injured adults lay scattered around the attack scene waiting for medical assistance.
‘‘Khan Beni Saad has become a disaster area because of this huge explosion,’’ Diyala resident Sayif Ali said. ‘‘This is the first day of Eid, hundreds of people got killed, many injured, and we are still searching for more bodies.’’
The Islamic State claimed responsibility for the attack in a statement posted on Twitter accounts associated with the militant group.
Iraq’s speaker of Parliament, Salim al-Jabouri, said Saturday that the attack has struck an ‘‘ugly sectarian chord,’’ and added that government is making ‘‘attempts to regulate Daesh’s terror from destabilizing Diyala security,’’ referring to the militant group by its Arabic acronym.
Several towns in Diyala were captured by the Islamic State last year. Iraqi forces and Kurdish fighters have since retaken those areas, but clashes between the militants and security forces continue.
‘‘We went out to the market for shopping and preparations for the holiday Eid in order to receive holiday cheer,’’ said another resident, who spoke anonymously for fear of retribution. ‘‘But this joy has turned to grief and we have lost family, friends, and relatives, all because of this government’s failure to provide us with security.’’
Security forces were out in full force across Diyala on Saturday, with dozens of new checkpoints and security protocols immediately implemented after Friday’s attack.
‘‘This horrible carnage is truly outside all boundaries of civilized behavior,’’ 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.
In August last year, at least 64 people were killed in an attack on a Sunni mosque in Diyala in what locals believed was a retaliatory attack against Diyala tribes that refused to proclaim loyalty to the Islamic State.
The United States has spent billions arming and training the Iraqi military, but it performed poorly last year when Islamic State militants swept across western and northern Iraq, routing four divisions.