Mali's ongoing fight against extremists
Frank Gardner looks at how Mali has been used by extremists as a base and how they have exploited its porous borders.
French troops have been based there since 2013 when they fought against Islamic militants who were controlling large parts of the country.
Malian security forces are hunting three suspects connected to an attack on a hotel in the capital, Bamako, on Friday, in which 19 people were killed.
Frank Gardner reports.