Aid workers have been giving details of the physical and psychological trauma suffered by ten slaves rescued on Monday by the authorities and human rights workers in the Tahoua region of northern Niger.

One human rights official, Iglass Weiller, said the ten men, women and children, who had been slaves all their lives, had suffered torture and starvation.

He said the owner of the slaves -- who has not yet been apprehended -- had raped the women and girls regularly.

A BBC correspondent in Niger says despite a prohibition against the centuries-old practice, keeping slaves is still widespread in many areas of northern Niger.

From the newsroom of the BBC World Service