President of the Republic of Mali Ibrahim Boubacar Keita announced his resignation early Wednesday morning hours after his arrest by troops in a sudden coup that followed a months-long political crisis in the fragile West African nation.

In an unprecedented development, “rebel soldiers” detained the President and Prime Minister Boubou Cisse on Tuesday afternoon sparking fears of a coup. The duo was then taken to a military base in the town of Kati, near the capital Bamako, which they had seized that morning.

The soldiers took up arms in the garrison town of Kati and detained senior military officers.

Protesters gathered in central Bamako in a show of support for the mutinous soldiers.

The M5-RFP opposition coalition, which has been one of the forces behind mass protests calling for Keita to resign, denied that a coup was in progress. A spokesman said the president’s detention was “not a military coup but a popular insurrection”.

“IBK (Keita) did not want to listen to his people. We even proposed an alternative but he responded with killings,” Nouhoum Togo, a spokesman for M5-RFP, told Reuters, referring to Keita by his initials.

Keita, who was democratically elected, has broad support from former colonial power France and other Western allies.

But the M5-RFP opposition along with the June 5 Movement – so named after the date of its first protest – have been marshaling deep-seated anger over a dire economy, perceived government corruption and Mali’s continuing battle against the unrest sown by regional jihadist groups.

In the wake of the developments, jubilant crowds in the city centre, who gathered to demand Keita’s resignation, had cheered the rebels as they made their way to the 75-year-old’s official residence.

Keita appeared calm as he appeared in a state television broadcast after midnight to declare the dissolution of the government and national assembly, and said he had no choice but to resign with immediate effect.

“If it pleased certain elements of our military to decide this should end with their intervention, do I really have a choice?” he said of the day’s events.

“(I must) submit to it, because I don’t want any bloodshed.”

It was unclear whether Keita was still in custody at the Kati base, which in a twist of fate was also the site of the 2012 putsch that brought the 75-year-old to power.

Meanwhile, neighbouring states, France and the European Union have all warned against any unconstitutional transfer of power as the coup played out on Tuesday.

UN Secretary General Antonio Guterres has demanded the “immediate and unconditional release” of Keita and Cisse as diplomats in New York said the Security Council is expected to hold emergency talks on Wednesday.

“The Secretary-General is following with deep concern the unfolding developments in Mali, including the military mutiny which culminated in the arrest of President Ibrahim Boubacar Keita and members of his government earlier today in Bamako,” said a statement issued by Stephane Dujarric, spokesman for Guterres.

The Economic Community for West African States (ECOWAS) condemned the coup in a statement, pledging to close land and air borders to Mali and push for sanctions against “all the putschists and their partners and collaborators”.

The 15-nation bloc — which includes Mali — also said that it would suspend the country from its internal decision-making bodies.

As the day unfolded, the United States and France released separate statements voicing deep concern about the turn of events and urged against regime change.

French President Emmanuel Macron had also discussed the crisis with his counterparts in Nigeria, Ivory Coast and Senegal and expressed his “full support for the ongoing mediation efforts of West African states”.

His office had added that he “condemned” the mutiny.

The US envoy to the region J. Peter Pham joined the calls for restraint and echoed its opposition to any “extraconstitutional” change.

Keita and Cisse’s sudden detention came on the heels of an apparently conciliatory message from the government in Bamako — which had urged the soldiers to engage in dialogue.

“The observed shifts in mood reflect a certain frustration that may have legitimate causes,” Cisse’s office said in a statement, without offering further details.

It added that the government was open to “fraternal dialogue in order to remove all misunderstandings”.

The drama coincided with opposition plans to resume protests against Keita.

Mali had been in the grip of a deep political impasse since June, and Keita had faced increasingly strident demands for his resignation.

The June 5 Movement, named for the date of its first protest, has channelled deep anger over a dire economy, perceived government corruption and a brutal jihadist conflict.

The opposition alliance’s anti-Keita campaign veered into crisis last month when at least 11 people were killed over three days of unrest that followed a demonstration.

Tensions flared in April when the government held a long-delayed parliamentary election, the results of which are still disputed.

The Economic Community for West African States (ECOWAS) had last month suggested the formation of a unity government while sticking by Keita, but the compromise was bluntly rejected by the opposition.