US soldiers can shoot to kill drivers who do not stop, according to reports from Iraq.
"All Iraqis are to be treated as hostile until proven otherwise," said Capt Dennis Carletta, a combat lawyer with the Judge Advocate Generals Corps, the US army's legal branch.
"Warning shots are to be fired. If a civilian vehicle doesn't stop, soldiers are free to shoot to kill," he added.
His comments demonstrate the "loosening" by US authorities of the rules of engagement, the laws under which their troops operate, after a suicide bomb killed four soldiers.
Failure to follow the rules of engagement could leave a serviceman open to prosecution.
All US soldiers were issued a card before the war - when there was a strong belief that the Iraqi people would be welcoming them as liberators - listing the conditions under which they could open fire.
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