Reid wasn't specific, but I'd bet it was the fedayeen--non-Iraqi fedayeen have been encountered before--Basra, I think.
Arnott reported just a little while ago that members of the Republican Guard (the Special RG, I think) are leaving Baghdad. He reported seeing 25ish year old men walking along the roadway, being noncommittal when questioned & another instance of a husband, wife & child in a car, all crying, with two 25ish year old men sitting calmly in the back seat of the car. Ken Allard said, "that's not good."