Four members of the Mississippi Army National Guard died Monday when a bomb exploded in Haswa, 30 miles south of Baghdad.
Guard spokesman Lt. Col. Tim Powell said Tuesday that the soldiers were from the 155th Brigade Combat Team.
The soldiers' names have not been released. Powell says families have been notified.
In accordance with Department of Defense policy, Powell says the identities of the soldiers and the circumstances surrounding their deaths will not be released for 24 hours after notification of relatives.
The 155th Brigade Combat Team is made up of 3,500 Mississippi Guard soldiers and others from Vermont and Arkansas.
The 155th is attached to the Second Marine Expeditionary Force and operates in the Karbala, Najaf and Babil provinces of Iraq.