The car bomb detonated in a market in the town of Abu Saydah in Diyala province. Residents have reported breathing problems, indicating the bomb may have dispersed poisonous fumes, such as chlorine gas which has been used in similar attacks.
U.S. military commanders have sent additional troops to Diyala in recent weeks, blaming a rise in violence on insurgents fleeing the security operation in Baghdad.
Major General William Caldwell told reporters in Baghdad that although additional forces have been sent to Diyala to help counter the insurgents, U.S. commanders are still focused on securing the capital.
"If in fact there are insurgent elements, outlaws, illegal groups that move out of the Baghdad area that allow for the conditions where economic progress, political progress, governance progress can take place and be established. What is key to all of this is the enduring piece of it."
The new Baghdad security plan calls for clearing areas of the city of insurgents and then setting up security stations to ensure militants do not return.
A new U.S. government report indicates that the increased number of U.S. troops and the new tactics of the Baghdad security plan have had little effect on the overall number of attacks in the country. The report from the Government Accountability Office is based on U.S. military data, and says there were an average of 157 attacks each day in March, and 149 per day in April.
Thousands of U.S. and Iraqi soldiers continue to search for three missing troops who are believed to have been captured by al-Qaida militants in an ambush Saturday. General Caldwell said commanders will evaluate the conditions that led to the soldiers capture, but right now the focus is on finding them.
"I cannot promise you the results that we are all praying for, but I can promise you that we and our Iraqi counterparts are doing everything we can to find out soldiers."
The general said coalition forces have questioned about 600 people and detained 11 during the search. U.S. commanders say the effort includes surveillance aircraft, spy satellites and house to house searches in the rural, predominantly Sunni, area south of Baghdad where the soldiers went missing.
