West African leaders have threatened military action against Niger's military junta after it took power in a coup last week

The leaders gave the junta seven days to reinstate President Mohamed Bazoum, who is being held captive.

Earlier, the junta warned it would resist any "plan of aggression against Niger" by regional or Western powers.

Meanwhile, hundreds of coup supporters protested outside the French embassy in the capital Niamey.

Leaders from Ecowas, the bloc of West African nations, held crisis talks in Nigeria on Sunday to discuss the latest coup - which follows army takeovers in neighbouring Mali and Burkina Faso.

A statement read out after the summit said that Ecowas had "zero tolerance" for coups.

The regional bloc would "take all measures necessary to restore constitutional order" if its demands were not met within a week.

"Such measures may include the use of force", and military chiefs are to meet "immediately" to plan for an intervention, the statement added.

The West African leaders also announced the immediate enforcement of a no-fly zone over Niger for all commercial flights, the closure of all land borders with the country, and the imposition of financial sanctions against the junta.

Ahead of their meeting, Gen Abdourahmane Tchiani - the head of the presidential guards unit who has declared himself Niger's new leader - warned Ecowas and unnamed Western nations against stepping in.

"We once again reiterate to Ecowas or any other adventurer our firm determination to defend our fatherland," the statement, which was read out on TV, said.

The coup has prompted concern that Niger, a former French colony, could pivot towards Russia.

The ousted president had worked closely with both regional and Western nations to fight militant Islamists in Niger.

Meanwhile Burkina Faso and Mali both moved closer to Russia after their own coups.

In Niamey, some of the protesters outside the French embassy chanted "Long live Russia", "Long live Putin" and "Down with France", AFP news agency reports.

France would not tolerate any attack on its interests in Niger, and would respond in an "immediate and intractable manner", President Emmanuel Macron's office said in a statement.