The car bomb in Khan Bani Saad, near the city of Baquba in central Iraq, also injured two police officers and three civilians, said provincial police Colonel Mudhafar al-Juburi.
Hadi al-Anbaki, an Iraqi journalist, told Aljazeera all roads leading to the explosion scene had been closed preventing reporters from approaching.
The US military also announced the death of a US marine killed by small arms fire in the strife-torn western city of Ramadi on Friday.
In Mosul, six people were wounded by a car bomb that set a house on fire, the US military said, without elaborating on the target of the attack. It was the fourth car bomb in Mosul in five days.
In Baghdad, armed men opened fire from a car, killing Hasib Zamil outside the Education Ministry offices in the Sadr City neighbourhood, education official Ibrahim Abid Wali said.
In Tikrit, thousands of supporters of Sunni Arab legislator Mashaan al-Jiburi assembled in a stadium to support his candidacy for the parliament speaker's post.
Lawmakers remain deadlocked on which Sunni Arab candidate should take the job, one day before their third session of the newly elected National Assembly.
Al-Jiburi has been nominated for
the parliamentary speaker post
On Wednesday, a group of Sunni leaders nominated al-Jiburi for the post, but it was not clear if he had the backing of the entire Sunni community. Lawmakers in other coalitions also voiced their opposition to his candidacy.
Some have called for naming Kurdish leader Jalal Talabani as Iraq's new president during the assembly session on Sunday, a step that would bring Iraq closer to forming a new government.