Clashes broke out between tribes and security forces in Karma district, Basra province, according to witnesses.
Reinforcements, ambulances and aircraft have headed to Karma.
Protesters held demonstrations to demand enhanced services and job opportunities.
Iraqi authorities have imposed a curfew in a number of cities.
This comes as sources said the situation in southern Iraq is getting out of control as angry protests are taking control of the provinces. Activists expressed concern the IRGC militia exploits the ongoing turmoil to spread terror and hamper oil transfers.