At least 12 people at Camp Bucca jail were hurt after the murder of one detainee sparked a mass brawl.
In Baghdad at least one civilian died and several others were hurt in a series of explosions, the US said.
A suicide car bomber attacked a US convoy in the western suburb of Mansour, and a bomb exploded in an eastern area, killing the civilian.
The attacks came the day after a double suicide car bombing in central Baghdad killed at least 15 people.
