Niger's military government said Thursday it foiled a late-night escape attempt by deposed President Mohamed Bazoum to flee to neighboring Nigeria after being held in custody for nearly three months following his ouster in a coup.

Bazoum had planned to escape with his family and two domestic staff at around 3:00 am Thursday, the junta said, with the help of some security accomplices who arranged transport for them to be moved to the outskirts of Niger's capital Niamey, from where they'll be flown in two helicopters "belonging to a foreign power" to Nigeria, it added in a statement.

"The prompt reaction of the defense and security forces made it possible to thwart this plan to destabilize our country," a junta spokesperson said, adding that "the main perpetrators and some of their accomplices have been arrested."

Bazoum's whereabouts are not immediately known.

The deposed Nigerien leader -- who has yet to resign as president-- had been placed under house arrest since the military junta overthrew him on July 27.

In August, Bazoum said in text messages sent to CNN with his consent that he had been isolated, kept without electricity, and forced to eat dry rice and pasta by his captors.

Later that month, the junta said it had "gathered the necessary evidence" to prosecute Bazoum for "high treason."

The junta has held on to power despite pressure from Niger's Western and regional allies.

Last week, the US said it was putting a hold on its assistance programs to Niger, including funding while formally declaring Bazoum's ouster as a coup.

The military rulers said they ovethrew Bazoum because of the country's security problems and struggling economy.

Niger's coup was the latest in successive power grabs by the military in the troubled West African Sahel region which has grappled for years with jihadist insurgency.