Witnesses described the bombing of an Italian base in the southern Iraqi city of Nasiriya as a devastating attack.
The force of the blast was huge
A BBC correspondent who managed to reach the scene said the entire front of the three-storey building appeared to have been torn off.
The blast threw up huge plumes of dust and smoke and shattered windows.
Italian and Romanian troops set up road blocks and small convoys of military vehicles and ambulances could be seen racing through the city.
Witnesses spoke of a huge detonation around 1030 local time (0730 GMT) this morning, when a truck approached along a riverside road, burst through the base's gate and exploded.
Coalition spokesman Andrea Angeli told the Associated Press news agency the force of the explosion was so strong that windows in buildings across the river from the base were blown out and vehicles parked outside burst into flames.
Secondary explosions from ammunition stored in the compound rocked the area moments after the main blast, he added.
One survivor spoke of his personal trauma following the blast.
"The front of my house is destroyed," Iraqi doctor Jamal Kadhim Shwail, who lives near the base, told Reuters news agency.
"I have just come back from the hospital where I operated on my own two daughters. It was a huge explosion.
"We are all in shock."
Some journalists described a tense atmosphere around the scene of the blast, with Italian police keeping the media from the scene.
BBC correspondent Paul Adams said the base may have been considered a soft target because it was lightly guarded and could be approached easily.
Poignantly, Iraqis told correspondents that the Italians were popular with residents, mingling freely with locals and proving friendly and approachable.