The number of people displaced by conflicts in Africa's Sahel has more than doubled in just over a year to a staggering 3.5 million, the United Nations has said.
At the beginning of 2014, the UN humanitarian agency had reported that around 1.6 million people were displaced across the nine Sahel countries: Burkina Faso, Cameroon, Chad, Gambia, Mali, Mauritania, Niger, Nigeria and Senegal.
The region is home to some of the world's poorest countries that have long been plagued by food insecurity, malnutrition and epidemics.
But UN Assistant Secretary General Robert Piper, who coordinates the UN's humanitarian work in the Sahel, warned that on top of those chronic crises the region was facing a "very troubling dynamic" in which displacement linked to conflicts was "really escalating dramatically."
Across the region, he told reporters in Geneva, "there is a very big increase in the number of people affected by conflict, who have been pushed from their homes and from their livelihoods as a result."
The violence by Boko Haram militants in northeastern Nigeria, and spilling over into neighbouring Cameroon, Chad and Niger, has spurred much of the displacement.
The Boko Haram insurgency has claimed at least 15,000 lives and forced some 1.5 million people to flee their homes since 2009.
Also fuelling displacement is the continued unrest in northern Mali, which has been dogged by violence from jihadists groups that seized control from Tuareg rebels before being routed by a French-led international intervention in 2013.
Around 150,000 Malians had fled to neighbouring countries by the middle of last year, while an equal number were displaced inside the country.
Despite peaceful elections after the French operation, the country remains divided and the north has seen a recent upsurge in attacks that has forced some 31,000 people from their homes in the past two weeks alone, the World Food Programme said Tuesday.
Conflicts outside the Sahel are also contributing to the displacement in the region, with violence in places like Darfur and the Central African Republic sending refugees fleeing into Sahel countries, Piper said.
The widespread displacement is taking a heavy toll on host communities which are themselves often poor and "extraordinarily vulnerable", he added.
In the southern Niger Diffa region, for instance, where more than half of inhabitants are already food insecure, a flood of Nigerian refugees has doubled the population, putting "tremendous pressure" on food, water and other resources, Piper said.
