Soldiers waved one of the vehicles through into al-Wahaeda district of Tal Afar when they saw it was laden with food supplies, after a one-week shortage.
The driver then blew up the vehicle, Ali Abboud, a doctor at the hospital treating the wounded, said.
George Bush, the US president, last year held up Tal Afar as a model for US-led efforts to create a stable Iraq.
"The chances of success [in Iraq] are essentially zero because the Iraqi people have no voice"
Non Sequitur, Cadiz, Spain
Send us your views
At least 17 people have been killed and dozens wounded after a suicide car bomb exploded outside a restaurant used by Iraqi police on a main road north of Ramadi.
A high-ranking police officer was reported to be among several policemen killed and wounded in the blast.
The blast, the latest in a string of such attacks in the western province of Anbar in recent months, struck an area where local tribes have been opposing al-Qaeda in Iraq.
Two suicide car bombs also exploded near the home of a tribal leader in the Abu Ghraib district west of Baghdad, killing the man's son and several other people, a provincial official said.
Sheikh Thahir al-Dari, whose home was the apparent target, is the head of al-Zobaie tribe and belongs to a group opposed to al-Qaeda in Iraq.
Ahmed al-Dulaimi, head of the provincial council media office in Anbar, said the sheikh's son was killed in Tuesday's double car bombing and there were several more casualties.
Salam al-Zobaie, Iraq's deputy prime minister, belongs to al-Dari's tribe.
The deputy prime minister survived an assassination bid last week.
Al-Zobaie was wounded in the attack at his home in Baghdad.
An aide said the suicide bomber was one of his own guards.
Mortar rounds slammed into a Shia area in Baghdad on Tuesday, killing at least four people and wounding 14, while sectarian clashes erupted for a fourth consecutive day south of the capital.
The mortar attack occurred in Abu Dasheer, a Shia enclave in the Sunni-dominated Dora neighbourhood in southern Baghdad. Police said those killed included two children, a woman and a man.
In Iskandariyah, 50km south of Baghdad, suspected Shia fighters broke into a Sunni mosque and planted explosives that damaged the gate and a fence, the police said.
|A truck carrying supplies for US forces |
was attacked in western Baghdad [EPA]
Clashes broke out about an hour later, leaving four Sunni fighters and one Shia fighter wounded.
The clashes were followed by a mortar attack on a nearby Shia mosque.
The rounds landed in a courtyard and did not damage the mosque, although a pedestrian was wounded.
A Shia man and his three sons also were wounded when a mortar round struck their house in Haswa, about 5km east of Iskandariyah.