France is setting up a base in northern Niger as part of an operation aimed at stopping al Qaeda-linked militants from crisscrossing the Sahel-Sahara region between southern Libya and Mauritania, officials said.

Paris, which has led efforts to push back Islamists in the region since intervening in its former colony Mali last year, redeployed troops across West Africa earlier this year to form a counter-terrorism force.

Under the new plan, about 3,000 French troops are now operating out of Mali, Burkina Faso, Niger and Chad — countries straddling the vast arid Sahel band — with the aim of stamping out Islamist fighters across the region. Another 1,000 soldiers are providing logistical support in Gabon and Senegal. […]