Thirteen people, including an army colonel, are facing charges in Madagascar over a foiled plot to assassinate President Michael Randrianirina.

Public prosecutor Narindra Rakotoniaina said 11 of the 13 were in custody, while Col. Patrick Rakatomamonjy, one of the main organizers, was yet to be arrested.

Rakotoniaina cited text and WhatsApp messages between the group as evidence of the plot, adding that the residences of some members were searched.

"Some of those arrested confessed that 20 billion ariary ($4.8 million) found in the bank accounts was to be used to execute their plans," Rakotoniaina was quoted by local newspaper L'Express De Madagascar on Friday.

Randrianirina, an army colonel, took office last October after a wave of youth-led protests over power and water shortages saw then-President Andry Rajoelina ousted and fleeing the Indian Ocean island nation.

On his visit to Malabo, Equatorial Guinea a week ago, Randrianirina told members of the Malagasy Diaspora that he and his wife were targets of assassination attempt and that arrests had been made.