"Four trucks were attacked in the Najme region between Diwaniyah and As-Samawah", the source said.
According to the security source, the trucks were carrying supplies from Basra to one of the US bases in Iraq.
Militants on pickup trucks attacked the supply convoy, forcing it to stop, got the drivers out of the vehicles, and set the convoy trucks on fire. All the convoy drivers were Iraqi citizens, the source said
The militants then left in an unknown direction, according to the security source.