Thousands of supporters of Niger's coup leaders gathered on Friday near a French military base on the outskirts of the capital Niamey, AFP reporters saw.
Protesters shouted "down with France, down with ECOWAS", a reference to the West African bloc which on Thursday approved deployment of a "standby force to restore constitutional order" in Niger.
Many brandished Russian and Niger flags and yelled their support for the country's new strongman, General Abdourahamane Tiani.
"We are going to make the French leave! ECOWAS isn't independent, it's being manipulated by France, there's outside influence," said one demonstrator, Aziz Rabeh Ali, a member of a students' union.
Niger's elected president, Mohamed Bazoum, was toppled on July 26 by members of his guard.
The move has been condemned by fellow countries in West Africa, the United Nations and Western countries, including France, the former colonial power and a close ally of Bazoum.
A hostile rally outside the French embassy on July 30 prompted France to organise voluntary evacuations of its citizens.
France has around 1,500 military personnel in Niger, sent to help the country in its eight-year-long struggle against a bloody jihadist insurgency.
Many are deployed in the air base near Niamey, a facility that is co-run with Niger's armed forces.
France last year pulled its forces out of neighbouring Mali and Burkina Faso, which are also battling jihadists, after falling out with juntas that ousted elected leaders.
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