Armed men on motorbikes killed more than 40 Tuareg civilians this week in northern Mali, where clashes over land and scarce water are common, an official said on Thursday.
The violence compounds an already dire security situation in the desert region used by armed groups to launch attacks in Mali and neighbouring countries in West and Central Africa.
The identity of the assailants was unknown, but disputes between the nomadic Tuareg and herder Fulani ethnic groups have killed several hundred and displaced thousands this year.