NIAMEY Niger's junta said on Thursday that it had thwarted an escape attempt by ousted President Mohamed Bazoum who has been imprisoned by the military since a July 26 coup despite international calls for his release.

The interim authorities said that Bazoum and his family, with the help of accomplices in the security forces, planned to drive a vehicle to the ouskirts of the capital Niamey and catch a helicopter to neighbouring Nigeria.

"The strong reaction of the defense and security forces made it possible to foil this plan to destabilize our country," a military spokesman said on national television.

Reuters was not able to confirm the account or reach Bazoum, whose whereabouts are unknown.

Niger's coup was one of five that have swept West Africa's central Sahel region in three years, leaving a vast band of arid terrain south of the Sahara Desert under the control of military rulers.

Like elected presidents in neighbouring Mali and Burkina Faso, Bazoum was pushed out in part because of mounting insecurity caused by an Islamist insurgency that has killed thousands in the region and which the military said it would be able to contain better than a civilian government.

Bazoum's party and family members say he has had no access to running water, electricity or fresh goods, prompting condemnation from former western allies.

(Reporting by Boureima Balima; Writing by Edward McAllister; editing by Diane Craft)