The Sahel region has been plagued for years by rebels linked to Al-Qaeda and the Islamic State group.

Five African nations -- Burkina Faso, Chad, Mali, Niger and Togo -- have since Monday been holding "a large national exercise at the special forces training centre" in Tillia, Niger's defence ministry said.

The drills include "tactical manoeuvres" and "initiatives aimed at strengthening ties with local populations", it added.

The exercise, which is due to run through June 3, marks the first joint military exercise between the five countries.

Military regimes in Burkina Faso, Niger and Mali have pushed out troops from France, the former colonial ruler, and are increasingly turning to Russia for support.

The countries set up a mutual defence pact, the Alliance of Sahel States, and in February announced their withdrawal from the West African bloc ECOWAS.

Successive coups in the three countries in recent years were driven by a deteriorating security situation, exacerbated by a humanitarian and political crisis.