A new alliance of Islamist militant groups linked to al Qaeda on Monday claimed responsibility.
French President Emmanuel Macron pledged France's full support for Mali.
Gunmen on Sunday attacked a luxury resort popular with Western expatriates just outside Mali's capital, Bamako.
At least 19 people were killed when Islamist attackers launched a car bomb and gun attack on a busy hotel.
Attack in Manchester killed at least 19, injured scores.