The soldiers, part of a 90-strong force called the Defence Force of Rutba, said they had refused to attend training because they feared reprisals from locals if they were seen to have cooperated with the Americans.

"We refused to go because we were afraid that when we came back to Rutba we would be killed," Taha Allawi, a former member of the unit, told Reuters. Rutba is in the far west of Iraq, close to the border with Jordan.

"The people here would believe that we were cooperating with U.S. forces and that is a reason for anyone to be killed."

A U.S. military official who oversees training said Iraqis who refused to attend courses could be dismissed, but said the decision rested with Iraq's Ministry of Defence.

"While coalition forces may have delivered the news, those decisions are made by the Ministry of Defence," said Lieutenant-Colonel Fred Wellman. "The United States does not disband units or dismiss soldiers."

Iraq's Defence Ministry had no immediate comment.

Another former soldier in the force, Ahmed Dhahi, said the disagreement began two months ago when the U.S. military first raised the idea of them attending training in Baghdad.

"They told us we had no right to refuse, they said the duty of soldiers was to obey orders, but we said 'We are Iraqis, not Americans, we don't follow orders from Americans'," he said.

"We did not want the locals to think that we were working with the Americans and then threaten us."

Dhahi said that once it became clear that the unit would not attend, the U.S. military took away their weapons, uniforms and identification tags and dismissed the force.

Iraqi units have fled the front line when ordered to fight insurgents before, but it was believed to be the first case of soldiers refusing to attend training for fear of reprisals.

Rutba, on the main highway heading to Jordan, is a predominantly Sunni Arab town with strong tribal allegiances. It has been the scene of occasional violence over the past two years, including attacks on military convoys.

A member of Rutba's local council said the soldiers, who had been receiving a salary of around $300 a month, were right to refuse to attend the course.

"The soldiers have all the right if they refuse to go because we understand the reason why they have taken this position," said Hamid Saleh al-Kubaisi.

"We have tried many times over the past two months to get the Americans to change their order, but they have insisted that they must go. The council has no affect on anything because the Americans don't listen."