France will evacuate French and European citizens from Niger, starting on Tuesday, its foreign ministry said, days after a junta seized power in the west African country.

The overthrow last Wednesday of President Mohamed Bazoum - the seventh military takeover in less than three years in West and Central Africa - has sent shockwaves across the region, pitting Niger's former Western allies against the likes of Russia and other junta leaders in the region.

Former colonial power France has had troops in the region for a decade helping to fight an Islamist insurgency, but some locals say they want the former colonial ruler to stop intervening in their affairs.

On Sunday, supporters of the junta burned French flags and attacked the French embassy in Niger's capital, Niamey, prompting police to fire volleys of tear gas in response.

"Considering the situation in Niamey, the violence against our embassy the day before yesterday and the fact that the air space is shut and our citizens cannot leave by their own means, France is preparing the evacuation of its citizens and (other) European citizens who want to leave the country," the foreign ministry said in a statement.

"The evacuation will start today," it said.

French Foreign Minister Catherine Colonna told BFM TV late on Monday that the protest in front of the embassy and the ensuing accusations that France shot at the crowd - which it denies - "have all the usual ingredients of destabilisation, the Russian-African way".

Yevgeny Prigozhin, the head of Russia's Wagner mercenary group, last week welcomed the coup in Niger, and said his forces were available to restore order.

The Kremlin said on Monday that the situation in Niger was "cause for serious concern" and called for a swift return to constitutional order.

According to the French foreign ministry website, there were just under 1,200 French nationals in Niger in 2022.

The coup has raised fears for the security of the Sahel region. Niger is the world's seventh-biggest producer of uranium, the radioactive metal widely used for nuclear energy and treating cancer.

Regional bloc ECOWAS has imposed sanctions, including a halt in all financial transactions and a national assets freeze, and said it could authorise force to reinstate Bazoum, who is still locked in his palace.

But the juntas of neighbouring Burkina Faso, Mali and Guinea all voiced their support for the coup's leaders on Monday.