Iraq ? An explosives-strapped man slipped into a luncheon gathering at a tribal leader’s home and blew himself up Friday, killing at least 23 people and wounding dozens.

The attack in Youssifiyah, in the area once known as the Triangle of Death because of its extreme violence, came a day after the United States relinquished the lead on security to Iraqi forces throughout the country. The bloodshed highlighted the challenge that Iraqi police and soldiers face in trying to bring order to a nation gripped by religious, ethnic and political enmity.

Police officials who spoke on condition of anonymity because they were not authorized to give information to news media placed the casualty tool at 30 dead and 110 wounded. But Iraqi Army Col. Aman Mansour Ibrahim, who was on the scene, said 24 were killed and 38 wounded. The U.S. military said Iraqis were reporting 23 dead and 32 wounded.