Islamic State (IS) militants have fired mortars on a crowded Shi'ite shrine north of Baghdad, creating a state of confusion that enabled three suicide bombers in military uniforms to infiltrate the compound and blow themselves up, Iraqi authorities say.
At least 37 people were killed and more than 62 were wounded, police and health officials said on July 8.
Iraqi Prime Minister Haidar al-Abadi has fired the three top security officials in Baghdad following a series of deadly attacks.
The latest attack occurred in Balad, about 90 kilometers from Baghdad, at the mausoleum of Sayyid Muhammad bin Ali al-Hadi. Crowds of pilgrims had gathered there to celebrate Eid al-Fitr, which ends the fasting month of Ramadan.
Two of the bombers detonated their explosives near the gate of the mausoleum, and a third rushed deeper into the shrine itself and threw hand grenades at pilgrims, the authorities said.
At least 20 militants then overwhelmed the police and militia guards and seized control of the compound for about a half-hour before reinforcements arrived from the federal and local police and members of the Popular Mobilization Forces, an irregular militia.
Those forces then clashed with the militants outside the shrine, killing at least seven, authorities said.
The IS group issued a statement claiming responsibility for the assault, which it said was carried out by three suicide bombers wearing explosive belts.
General Imad al-Zihiri, the commander of security operations in the nearby city of Samarra, told The New York Times that "a security breach took place in Balad targeting the mausoleum of Sayyid Muhammad bin Ali al-Hadi, but our forces managed to recontrol the situation."
Dhamin al-Jibouri, the police commander of Salah al-Din Province, where Balad is located, told the Times that the bombers wore "military uniforms to disguise."
He added, "We don’t know yet what happened to the rest of the militants, but we are controlling the area again."
The authorities said the mausoleum was not believed to be seriously damaged, though the third bomber came within several meters of the tomb of the imam. Outside, however, the bombs ignited fires in a marketplace.
The weekend attack in Baghdad was the worst in Iraq since the U.S.-led invasion of 2003. IS took responsibility for that bombing, in the Karrada district, which was teeming with revelers celebrating the end of Ramadan, including many families with children.
The Islamic State claimed that the bombing had killed a gathering of Shi'ite Muslims. But Karrada is a mixed area where Iraqis of all identities gather, and many Sunnis were also killed.
Assaults against Shi'a by Sunni extremists make it difficult for Prime Minister Haidar al-Abadi, a Shi'a, to achieve meaningful progress in reconciling Iraq’s majority Shi'a with Sunnis, even as his armed forces have won victories against IS militants on the battlefield.
After the attack on the mausoleum, Muqtada al-Sadr, a powerful Shi'ite cleric, ordered his "peace brigades" to Balad to "protect innocents' lives."
"This is another terrorist brutal attack against our" holy places, he said.