The violence in Al-Uzair district, south of Amarah in the southeastern province of Maysan, lasted several hours, said Saad al-Zaidi, police spokesman for the area.

The soldier was from one of the two tribes and had been "on leave when the conflict broke out because of disputes over farmland", he told AFP.

Despite beefed up security measures, Maysan province, which borders Iran, is a route for drug traffickers where tribal rivalry often degenerates into violence.

In May, eight people were killed in the same region when clashes between members of the same tribe broke out over farmland.

Further complicating the task of law enforcement, assassinations or attempted assassinations targeting judges or police officers are also commonplace.