State radio in Niger says fifteen herdsmen have been killed and four injured in an attack by Tuareg nomads from Mali.

The radio said the Tuareg raiders, armed with rifles, attacked camps in the south-western Abala region early on Saturday, and made off with cattle and other livestock.

Correspondents say such clashes have long been a problem in the area, as herdsmen vie for water and grazing rights.

In March last year, more than twenty-two herdsmen in Niger were killed by Malian Tuaregs in a fight over a watering hole.