Benin President Patrice Talon said on Sunday that the West African nation's government and armed forces had thwarted a coup attempt by a group of soldiers and vowed to punish them.

Talon's announcement on Sunday evening came about 12 hours after gunfire first rang out in several neighbourhoods of Cotonou, the country's biggest city and commercial hub, and soldiers went on state television to say they had removed Talon from power.

Forces loyal to Talon "stood firm, recaptured our positions, and cleared the last pockets of resistance held by the mutineers," Talon said in his own televised statement.

"This commitment and mobilization enabled us to defeat these adventurers and to prevent the worst for our country... This treachery will not go unpunished."

Talon said his thoughts were with victims of the coup attempt as well as with a number of people held by the fleeing mutineers, without giving details. Reuters was unable to verify if there were casualties or hostages.

The unrest was the latest threat to democratic rule in the region, where militaries have in recent years seized power in Benin's neighbours Niger and Burkina Faso, as well as in Mali, Guinea and, only last month, Guinea-Bissau.

But it was an unexpected development in Benin, where the last successful coup took place in 1972.

A government spokesperson, Wilfried Leandre Houngbedji, said that 14 people had been arrested in connection with the coup attempt as of Sunday afternoon, without providing details.

At the request of Talon's government, Nigeria sent air force fighter jets to take over Benin's airspace to help dislodge the coup plotters from the state television network and a military camp, a statement from Nigerian President Bola Tinubu's office said.

Nigeria has also sent ground troops, the statement said.

West Africa's regional bloc ECOWAS and the African Union condemned the coup attempt.

In a subsequent statement, ECOWAS said it had ordered the immediate deployment of elements of its standby force to Benin, including troops from Nigeria, Sierra Leone, Ivory Coast and Ghana.

Gunfire, explosions rattle biggest city

At least eight soldiers, several holding weapons, had appeared on state television on Sunday morning to announce that a military committee led by Colonel Tigri Pascal was dissolving national institutions, suspending the constitution and closing air, land and maritime borders.

"The army solemnly commits to give the Beninese people the hope of a truly new era, where fraternity, justice and work prevail," the soldiers' statement said.

The soldiers mentioned the deteriorating security situation in northern Benin "coupled with the disregard and neglect of our fallen brothers-in-arms."

Talon has been credited with reviving the economy since taking office in 2016, but the country has also seen an increase in attacks by jihadist militants that have wreaked havoc in Mali and Burkina Faso.

Foreign Minister Olushegun Adjadi Bakari told Reuters that the soldiers had only managed to briefly take control of the state TV network.

Gunfire could be heard early Sunday in several neighbourhoods of Cotonou as residents were trying to make their way to church.

The French embassy said gunfire had been reported near Talon's residence in Cotonou and urged citizens to stay at home.

By early afternoon, police were deployed at major intersections in the city centre.

Narcisse, a furniture salesman in Cotonou who gave only his first name for safety reasons, said he first heard gunshots at 8 a.m. (0700 GMT) and soon saw police officers speeding past.

"I got scared and brought my sofas inside and closed. It's a bit calmer now, which is why I reopened," he said.

More gunfire and explosions were heard in Cotonou early Sunday evening, witnesses said, but the sounds had stopped before Talon's statement was broadcast.

Elections on horizon

Benin is preparing for a presidential election in April that is expected to mark the end of Talon's tenure.

Last month, Benin adopted a new constitution creating a Senate and extending the presidential mandate from five to seven years, in what critics said was a power grab by the ruling coalition, which has nominated Finance Minister Romuald Wadagni to be its candidate.

The opposition Democrats party, founded by Talon's predecessor Thomas Boni Yayi, saw its proposed candidate rejected because of what a court ruled was insufficient backing from lawmakers.

The deteriorating security situation in the north was likely a factor behind the soldiers' actions, said Nina Wilen, director for the Africa Programme at the Egmont Institute for International Relations in Belgium.

Benin has been the hardest hit among coastal West African states by jihadist groups that have made major gains in the central Sahel, she said, a fact underscored by major attacks in January and April that killed dozens of soldiers.

Nevertheless, she said Sunday's coup attempt was a surprise given Benin's relative stability following a spate of coups and coup attempts in the first decades after independence from France in 1960.

"No coups in 50 years? That's a major feat for a country in West Africa," she said.