France has condemned violence against its diplomatic mission in Niger and pledged to react strongly to any attack on its nationals or interests, as anti-French protests took place outside the French Embassy in Niamey on Sunday following last week's military coup.

"The President will not tolerate any attack against France and its interests," President Emmanuel Macron's office said in a statement, specifying that it would respond to attacks against French diplomats, armed forces or businesses.

In a separate statement, the Foreign Affairs ministry condemned all violence against diplomatic missions and called on Niger authorities to protect the French mission as required under international law.

Between 500 and 600 French nationals are currently in Niamey, according to the Foreign Ministry.

Journalist Georges Attino tweeted video showing large numbers of people gathering in Niamey in support of the putschists. National television rebroadcast the demonstration live.

Some of the protesters outside the French embassy chanted "Long live Russia", "Long live Putin" and "Down with France", according to France's AFP news agency.

Macron has spoken with ousted President Mohamed Bazoum and former president of Niger Mahamadou Issoufou in the last few hours, the statement from the president's office said, adding that both of them condemned the coup and called for calm.

France, the former colonial power in Niger, announced on Saturday it was cutting all development aid to the country and called for Bazoum to be returned to office following his ouster late on Wednesday.

Niger has been a security partner of France, and the United States, which have used it as a base to fight an Islamist insurgency in West and Central Africa's wider Sahel region.

France has 1,500 troops stationed in Niger, which up until now work hand in hand with Niger's army.

(with newswires)