I can only go on the news reports that I saw on TV, just the same as you saw. I don't have any inside information. As I understand it, an American convoy was rolling through Kabul and going at relatively high speed. I listened to the reporters saying that they're doing that because they don't want to slow down because they may get into difficulties. Apparently one of these vehicles hit a taxi and killed--I don't know if there's more than one--at least one individual, and a riot broke out. That's all I understand that happened there.
On May 30th, 2006. See this statement in context.