The military junta in Niger was given a one-week ultimatum to cede power by West African states who warned that they still did not rule out the "use of force" and imposed immediate financial sanctions.

The 15-nation Economic Community of West African States (ECOWAS) called on Sunday for the "immediate release and reinstatement" of elected President Mohamed Bazoum, held by the military since last Wednesday. 

In a statement after its summit in Abuja, Nigeria, on Sunday, ECOWAS said, "In the event the authorities' demands are not met within one week (ECOWAS will) take all measures necessary to restore constitutional order in the Republic of Niger. Such measures may include the use of force. For this effect, the chiefs of defence staff of ECOWAS are to meet immediately."

Niger's assets in ECOWAS central and commercial banks were frozen and a "travel ban and asset freeze for the military officials involved in the coup attempt" was also imposed.

"The same applies to their family members and the civilians who accept to participate in any institutions or government established by these military officials," said the statement.

On its part, Niger's junta warned that ECOWAS could stage an imminent military intervention in the capital Niamey as General Abdourahamane Tiani, the chief of the powerful presidential guard, declared himself leader.

Meanwhile, a Chad government spokesman told AFP that the president of Chad, General Mahamat Idriss Deby Itno, was on Sunday in Niger to help resolve the crisis in the country.

Itno was in the capital Niamey "to see what he could bring to solving the crisis," Aziz Mahamat Saleh said, adding that the trip was on the initiative of Chad, which neighbors Niger.

President Mohamed Bazoum was detained at his residence and talks to release him failed, a presidential source said. The soldiers have declared the suspension of all institutions, closed borders, and imposed a curfew. They cited reasons such as the deteriorating security situation and poor economic and social governance as justification for ending President Bazoum's rule.

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Former colonizer France and the European Union suspended security cooperation and financial aid to Niger after the coup started, while the US threatened to cut aid as well. 

In a statement on national television on Saturday, Niger junta member Amadou Abdramane claimed that the summit's aim was to "approve a plan of aggression against Niger, in the form of an imminent military intervention in Niamey," which would be "in cooperation with African countries who are not members of the regional body and certain Western nations". 

'Down with France'

This comes as thousands of pro-junta protesters protested outside the French embassy in Niamey on Sunday, and an AFP journalist reported that some were trying to enter the building.

Some demonstrators replaced the plaque saying "Embassy of France in Niger", with Niger and Russian flags, while others yelled "Long live Russia," "Long live Putin," and "Down with France."

Bola Tinubu, president of Nigeria and ECOWAS chairman, said two days ago that ECOWAS and the international community "would do everything to defend democracy and ensure democratic governance continues to take firm root in the region."

US Secretary of State Antony Blinken spoke to Tinubu ahead of the summit to relay his "deep concern" over the Niger situation and "underscored his support for President Tinubu's continued efforts to restore constitutional order."

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Tiani said the putsch in Niger was a reply to "the degradation of the security situation" connected to bloodshed, corruption, and economic woes.

Retaliation possible

In response, France threatened retaliation on Sunday if its citizens were attacked after protesters tried to enter its embassy in Niamey.

"Should anyone attack French nationals, the army, diplomats and French interests, they will see France respond in an immediate and intractable manner," the French President's office said, continuing that French President Emmanuel Macron "will not tolerate any attack against France and its interests."

"France also supports all regional initiatives" intended at "restoring constitutional order" and returning Niger President Mohamed Bazoum.