Libya's interim government says a ceasefire has been reached in a six-day conflict between two tribes that has claimed some 150 lives in the southern city of Sabha. However, the violence exposes the government's tenuous grasp in the country.

Premier Minister Abdel Rahim al-Kib told reporters in the capital Tripoli that "calm now prevails in Sabha." Previous ceasefires had been announced throughout the week, but collapsed within hours each time, as deep-seated local tensions erupted into violence.

The conflict in Sabha is between the indigenous Arabic population and the Tubu, a tribe that stretches through Niger, Chad and Libya itself, though its members are regarded as outsiders by many in the city.