More than 1,000 are being held in horrific conditions, facing disease, malnutrition and torture, as part of Cameroon's crackdown on Boko Haram, Amnesty International charges.
Nearly 150, including 11 children, have died this year in Nigeria's military detention barracks, mostly due to starvation and dehydration, Amnesty International reports.
As Boko Haram continues its campaign of suicide attacks in northern Cameroon, the army is enforcing a "free-fire zone" along the Nigerian border, claiming still more local lives.
As yet another Boko Haram attack left 30 dead at a vegetable market, Nigerian activists decried the disparity in online and media response with the Paris attacks.
The Pentagon has dispatched the first contingent of a 300-strong force to northern Cameroon, where they are to provide intelligence for the regional military alliance against Boko Haram.
Coordinated suicide attacks left over 40 dead in villages in western Chad and northern Cameroon that host thousands of Nigerian refugees who have fled Boko Haram violence.
A report by Amnesty International details atrocities committed by Boko Haram in northern Cameroon, resulting in the killing of at least 400 civilians over the past months.
Boko Haram, now calling itself Islamic State West Africa, carried out a wave of deadly suicide bombings as a multilateral military alliance prepares to take the field against the jihadists.
After twin deadly suicide bombings by two women wearing burqas, authorities in Northern Cameroon have banned women from wearing burqas and face-covering veils.