Niger's president says several political and military officials have been arrested because of a coup attempt overnight Saturday.

President Mahamadou Issoufou said Thursday investigations have been opened and more arrests will be made after the aborted attempt overnight Saturday. He said arrests were made in the army ranks and of a former chief of staff.

Issoufou warned a political vacuum could lead to a takeover by Islamic extremists, referencing Mail's unrest. Niger has seen extremist attacks for years, most recently by Boko Haram.

Niger has a long tradition of strongmen seizing power by force. A 2011 vote marked the home stretch of the third post-coup transition to civilian rule the country has undertaken since 1993.

The government on Tuesday signed a draft decree setting new elections for Feb. 21, 2016.