Wednesday's attack on an Iraqi National Guard encampment near Ana, 260km from Baghdad on the main highway to Syria, wounded up to 24 others.
Witnesses told Aljazeera that the bomber struck when people were lining up to volunteer for the force.
Earlier on Wednesday, in the southern Iraqi city of Basra, an Iraqi civilian was killed when a bomb exploded on a bridge.
Police Lieutenant-Colonel Karim al-Zaidi said the bomb targeted an Iraqi police vehicle, wounding the four occupants and killing a civilian who was driving past.
British forces in the mainly Shia Basra region often use the Quzayzi bridge where the bomb went off, but there were no troops in the area at the time.
In Falluja, US warplanes struck again overnight Tuesday.
Three houses were flattened in the attack in the Muatasim area, an Iraqi journalist told Aljazeera.
The repeated bombing of Falluja
has left many homes destroyed
But the families who lived there had already fled to a safer area and there were no casualties, said Dr Dhiya al-Jumaili of Falluja General Hospital.
The US military said in a statement a suspected safe-house of Abu Musab al-Zarqawi group was targeted, south-west of Falluja.
It was the latest in weeks of strikes on the city, 65km west of Baghdad, that have left scores dead and injured.
More than half of Falluja's residents have fled the city due to continuous bombings.
Talks between a delegation representing the city's residents and officials of the interim Iraqi government are continuing, the Iraqi journalist told Aljazeera.
On Tuesday, interim Prime Minister Iyad Allawi reportedly sounded a warning to fighters in Falluja and the neighbouring city of Ramadi to shun violence or face the consequences.
His comments came after hospital sources said nine people, including women and children, were killed in two pre-dawn raids by US warplanes on suspected targets in Falluja on Monday.
US forces also bombed Sadr City in Baghdad late on Tuesday.
Meanwhile, three members of the Patriotic Union of Kurdistan Party were killed and two others injured on Tuesday in the Jalawla area, north-east of Baquba city, when unknown assailants opened fire on them.
An Iraqi group has said it had kidnapped a member of the Kurdistan Democratic Party (KDP) who it described as a "spy" working as a translator for the US army, according to an Internet statement posted on Wednesday.
"The body was found with a tag attached to it saying he worked for the US Army"
Bilal Dulaimi, police officer
The Army of Ansar al-Sunna, which last month posted a video tape of the apparent beheading of what it said were three KDP members, said in the statement that it had abducted Luqman Husain Muhammad in the western city of Ramadi on 5 October.
"He said he participated in the questioning of jailed Iraqi mujahidin and also in US raids of homes of Muslims in Ramadi," said the statement which was dated Wednesday and carried on a website often used by Islamists.
It was not possible to verify the statement's authenticity.
The KDP is one of two main Kurdish groups represented in Iraq's interim government.
Also in Ramadi, police said they found the bullet-ridden body of an Iraqi working as an interpreter for the US military.
"The body was found with a tag attached to it saying he worked for the US Army," said Bilal Dulaimi, a police officer in the city.
He said the corpse was taken to the main hospital in Ramadi, which has been the scene of frequent clashes between US troops and Iraqi fighters.