Six people, including the soldier, were killed during a clash between two tribes sparked by a dispute over agricultural land, said Saad al-Zaidi, police spokesman for the area.

The violence in Al-Uzair district, south of Amarah in the southeastern province of Maysan, lasted several hours, Zaidi told AFP.

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 added.

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 north, in Wasit province, an armed clash between members of the same tribe left three people dead and three others wounded, said Ali Hussein al-Sarai of the local police force.

The violence, which took place in the town of Al-Dubuni, broke out over a dispute between two sides over the right to marry a young woman, he said.

Millions of people belong to tribes in Iraq, which are marked by strong patriarchy.

Violence between tribes, or within the same clan, is frequent in Iraq and often occurs without involvement by law enforcement bodies.