An American helicopter strike in Baghdad's crowded Shi'ite slum of Sadr City killed 32 people on Wednesday, a statement said. Iraqi officials earlier told Reuters it had received 13 bodies. Police put the death toll at 11 and said it included women and children.
An official in the office of Shi'ite cleric Moqtada al-Sadr said U.S. aircraft had attacked Sadr City's Tareq neighbourhood before dawn. Hundreds of angry mourners chanted as they carried at least three coffins, draped in Iraqi flags, through Sadr City streets. Family members wept.
The U.S. military said the raid targeted fighters from breakaway factions of Shiite cleric Muqtada al-Sadr's Mahdi Army. At least 12 people were detained by the American forces. "The individuals detained and the terrorists killed during the raid are believed to be members of a cell of a special groups terrorist network known for facilitating the transport of weapons and explosively formed penetrators, or EFPs, from Iran to Iraq, as well as bringing militants from Iraq into Iran for terrorist training," the military said.
The American statement said the main suspect in the raid was a liaison between Iraqi fighters and Iran's elite Quds Force, which is accused of arming and training the militants. Tehran has denied allegations that it is supporting the violence in Iraq.
Baghdad police imposed a three-day vehicle curfew on Wednesday morning, ahead of an annual pilgrimage to a north Baghdad Shi'ite shrine.
Meanwhile, Iraqi Prime Minister Nouri al-Maliki arrived in Iran on Wednesday for talks set to focus on bilateral relations and overcoming "terrorism challenges" in Iraq. It was the Iraqi premier's second visit to Tehran in less than a year.
The U.S. has accused Iran of providing money and weapons to Shiite militias in Iraq, but Tehran denies the charges.
State television said he was received in Tehran by First Vice-President Parviz Davoodi and would hold talks with other Iranian leaders during his visit, expected to last three days, the AP reported. "We are here today to boost commercial and security relations with neighboring countries against the terrorism challenges in the area," al-Maliki told The Associated Press on the plane to Iran.
The premier said he would also discuss and sign a number of cooperation memorandums with Tehran.