Sahel does mean something like the Sahara region.
France to send 600 more troops to fight armed groups in Sahel
Planned deployment would bring French military presence in Africa's Sahel region to 5,100 troops.
France has said it would boost its military presence in the Sahel by adding 600 troops to its 4,500-strong operation in Mali and four other countries in the region.
Defence Minister Florence Parly said in a statement on Sunday that the bulk of the reinforcements would be deployed by the end of February in the border zone linking Mali, Burkina Faso and Niger to counter increasing violence carried out by armed groups.
Read more at: https://www.aljazeera.com/news/2020/02/france-send-600-troops-fight-armed-groups-sahel-200202143520086.html
