A UN briefing on Friday called for an end to the violence in West Africa’s Sahel region, where more than two million people have been displaced within the borders of their own countries.

Boris Cheshirkov, a spokesperson for the Office of the UN High Commissioner for Refugees (UNHCR), said that the number of internally displaced persons in the region has quadrupled in just two years. The region, which includes the nations of Burkina Faso, Chad, Mali, and Niger, has been wracked by violence from armed insurgent groups like al-Qaeda and the Islamic State, criminal gangs, as well as possible extrajudicial killings by government forces.

The latest attacks have hit the locality of Koumbri in the northern part of Burkina Faso, resulting in more than 11,000 people fleeing their homes for the communities of Ouahigouya and Barga that are approximately 35 kilometers away. Many of those displaced have been forced to sleep outside due to a lack of adequate shelter. UNHCR is currently working to construct 108 new shelters, but it noted that the “humanitarian response is dangerously overstretched” and called on other nations to act “to redouble … support for the region.”