For Monday's paper, the New York Times has this report. I find this stunning, and a terrible harbinger of what lies in store for our troops.
UPDATE [7:12 EST]: The article has been extended and updated considerably in the hour since I put up this diary, and the story has become stranger and stranger. Since the NYT may still be editing, I recommend following the link to see where it is going . . .
New details did emerge today about clashes in the Shiite holy city of Karbala, which left five Americans dead on Saturday. Lt. Col. Scott R. Bleichwehl, an American military spokesman, said the gunmen who stormed the provincial governor’s office during a meeting between American and local officials were wearing American military uniforms in an effort to impersonate United States soldiers. [Ed: Duh!]
... [A]ccording Iraqi officials [sic], the gunmen disguised their intent with military uniforms, American flak jackets, guns and a convoy of at least seven GMC sport utility vehicles.
Karbala’s provincial governor, Akeel al-Khazaali, said the local police at a checkpoint on the city’s edge waved the vehicles through because they believed they held important Americans.... One sport utility vehicle had a sign on its back window warning drivers to stay back, in English and Arabic, the authorities said, a carbon copy of what some official American vehicles use.
The sophisticated, brazen attack hinted at what could be a new threat for American troops as they start a fresh security plan centered on small bases in Baghdad’s bloodiest neighborhoods, where troops will live and work with Iraqi forces. One of the American military’s greatest concerns is that troops will be vulnerable to attack from killers who appear to be colleagues.
I have to assume that this has already been diaried, but I haven't seen it. I will delete as soon as someone points it out to me. I actually got the link originally from demetroula's diary, but that author focuses on the volume of the casualties Saturday, not the methods used.