George W. Bush yesterday sought to rebut increasingly widespread rumours that his administration was preparing some kind of military action against Iran. Mr Bush confirmed a report in yesterday's Washington Post that he had authorised US troops to shoot and kill Iranian operatives in Iraq, but denied this was a prelude to stronger action.

"We believe we can solve our problems with Iran diplomatically," said the US president. "It makes sense that if somebody is trying to harm our troops, or stop us from achieving our goal, or killing innocent citizens in Iraq, that we will stop them."