A suicide bomber waiting to be searched outside a mosque has reportedly taken at least 12 lives south of Baghdad.
A doctor at a local hospital says another 18 people are wounded.
The mosque involved is run by the anti-American cleric Muqtada al-Sadr, who is Shiite. There's no claim of responsibility yet, but suicide bombings in Iraq have been associated with Sunni extremists.
A sheik says the attack is one of the consequences of the new security agreement with the U.S. that was approved yesterday by parliament. He says as long as American troops remain in the country, "Iraq will be still a battlefield."
The province where the bombing happened was turned over to Iraqi forces last month.