Officers in Niger declared the commander of the presidential guard, General Abdourahamane Tiani, the head of a new military government on Friday, two days after the unit seized elected President Mohamed Bazoum in a coup d'etat.
In a televised statement, the coup leaders said they had suspended the constitution and dissolved the government.
Tiani was the head of the presidential guard that shut Bazoum in his palace on Wednesday, then declared it had ousted him because of poor governance and worsening security.
The general appeared on state television on Friday, described as the president of a newly formed military council, the National Council for Safeguarding the Homeland (CNSP).
"The President of the CNSP is the head of state. He represents the state of Niger in international relations," said a statement read by an officer.
The constitution has been suspended and the government dissolved, and the CNSP will exercise all legislative and executive power, according to the statement.
While the motives of the coup leaders remain unclear, it is rumoured that they were driven into action by an attempt to force out Tiani, who is also known by the name Omar Tiani.
International alarm
African countries and Western powers have reacted with alarm to the events in Niger, insisting that constitutional order be restored.
Niger borders three countries – Mali, Burkina Faso and Chad – that have also experienced military coups in the last two years.
Before the uprising this week, it was seen as the West's most stable partner in a region facing a growing Islamist insurgency.
Some 1,500 French troops are stationed in Niger as part of the fight against jihadist rebels in the Sahel.
France turned to Niger after it was forced to withdraw from Mali following a breakdown in relations between Paris and the military junta there.
Earlier on Friday, French President Emmanuel Macron described the coup as "dangerous" for the volatile Sahel region.
"This coup is completely illegitimate and profoundly dangerous, for Nigeriens, for Niger and for the whole region," Macron said.
Macron said he had spoken to Bazoum, who is still being held in his palace, and called for him to be reinstated.
The French president also said that Bazoum is in good health.
(with Reuters and AFP)