An IED?
The Slimes and others reported that the driver was shot.
If this was an IED, the two soldiers missing may be dead.
Here's the report from DoD:
http://www.defenselink.mil/news/Jun2006/20060616_5440.html
Even it doesn't specify whether it was an IED or gunfire..it says there were explosions and gunfire "in the area"..