The authorities in Mali say gunmen have killed more than 30 ethnic Fulani civilians in the central Mopti region.
A government statement said the attackers, dressed as traditional hunters, raided their village early on Tuesday morning.
Some of those killed were children.
The violence is linked to longstanding competition over land and water in Mali, and the presence of Islamist armed groups.
France helped Malian forces stave off a jihadist insurgency that took control of large parts of the troubled north in 2012.