Who are JNIM, the jihadist ‘ghost enemy’ gaining momentum in the Sahel?

Malians near the site of an attack by JNIM in Bamako last September. The group has found support in communities targeted by military regimes. Photograph: Hadama Diakite/EPA

The scene is wearily familiar. It is dusk at a ramshackle military outpost, surrounded by miles of scrubby desert or on the outskirts of a major town.

Suddenly, there is the sound of automatic rifle fire, and hundreds of men arriving on motorbikes, then explosions, screams, fire, smoke. The defenders flee or are killed. The attackers shout triumphant cries of “God is Greatest”.