The U.S. military says al-Qaida was likely responsible for the multiple bombings in northern Iraq Tuesday that killed more than 200 people.
The military made the comment on Wednesday, less than a day after four suicide truck bombers struck nearly simultaneously west of the city of Mosul.
The attack targeted members of the Yazidi minority, which is a Kurdish religious sect of ancient origin.
Rescuers continue to search through the rubble for people trapped in the debris. Officials say the death toll could rise.
The White House condemned the bombings as "barbaric attacks on innocent civilians."
In other news, Iraqi police say a suicide car bomber struck a judge's convoy south of Baghdad, killing two bodyguards and wounding seven other people, including the judge.
The attack occurred near the judge, Aqeel Adnan Witwit's home in the town of Hillah, about 95 kilometers south of Baghdad.
In other news, the U.S. military says coalition forces killed 11 suspected al-Qaida in Iraq terrorists and detained four others in Baghdad and north of the capital on Wednesday.
The U.S. military announced Tuesday the deaths of 10 U.S. troops in Iraq, including five killed when their helicopter crashed. A statement said the CH-47 Chinook transport helicopter went down while conducting a routine test flight near an airbase west of Baghdad.