The attack comes amid a dispute between Iraq's Shiite and Sunni endowments, which manage the country's religious landmarks, over a shrine north of Baghdad, and a protracted political standoff that has raised sectarian tensions in a country racked by brutal communal bloodshed from 2006 to 2008.
Today's attack struck at 11:00 am (0800 GMT) outside the Shiite endowment in Baab al-Muadham, central Baghdad, and left at least 22 people dead and more than 65 wounded, two medical officials said.
The bombing completely destroyed the endowment headquarters, its deputy chief, Sami al-Massudi, told AFP. "We do not accuse anyone, but we call on the Iraqi people and especially on the sons of our religion to bury the strife because there is a plan to launch a civil war between the people, and between the Iraqi sects," Massudi said.
He said the Shiite endowment had received threats in recent days as a result of the dispute over the Al-Askari shrine, a Shiite Muslim site in the mostly Sunni city of Samarra, north of Baghdad.
The iconic gold-domed shrine was hit by a brutal al-Qaeda suicide attack in February 2006 that ignited the country's bloody confessional violence.
Massudi and his aides had produced documents in recent days that attributed the management of the shrine to the Shiite religious endowment, sparking tensions with its Sunni counterpart.