Burkina Faso’s toppled interim president, Michel Kafando, has resumed power after a week-long coup by renegade troops who caved under pressure from regional powers and France, the country’s former colonial ruler.

The move came after marathon talks in Abuja, the capital of regional heavyweight Nigeria, brokered by the Economic Community of West African States (Ecowas), and threats by the French president, François Hollande, that the coup leaders should surrender immediately or face the "consequences”, including possible sanctions.

"The transition has been restored and this very minute I am resuming the exercise of power,” Kafando said.

Six Ecowas heads of state were arriving in the Burkinabe capital of Ouagadougou to oversee the formal reinstallation of Kafando and to try to solve two contentious issues: an amnesty plan for the putschists, and whether upcoming elections should be open to supporters of the previously deposed dictator, Blaise Compaoré.

Kafando said the regional leaders would "take into account the will of the Burkinabe people” in their new mediation bid.

The deal to restore the interim administration to power was signed overnight after troops entered Ouagadougou, turning up the pressure on the elite presidential guards (RSP) who staged the coup. Under its terms, the RSP agreed to stand down from the positions they had taken up in Ouagadougou, while the army also agreed to withdraw its troops and guarantee the safety of the RSP members as well as their families.

The accord was presented to the Mogho Naba, the king of Burkina Faso’s leading Mossi tribe, in front of the media early on Wednesday.

The country was plunged into crisis last Wednesday when the powerful RSP detained the interim leaders who had been running the country since a popular uprising deposed the iron-fisted president Compaoré last October after his failed bid to extend his 27-year rule.

The elite unit of 1,300 men loyal to Compaoré officially declared a coup on Thursday and installed the rebel leader, General Gilbert Diendéré, Compaoré’s former chief of staff, as the country’s new leader.

The breakthrough came as Diendéré told AFP that Kafando, who had been seized by presidential guards but later released, would be returned to office on Wednesday. The return of Kafando is "already a done deal,” he said late on Tuesday. "The [African] heads of state arrive tomorrow to put him back in office.”

The putsch came just weeks ahead of an election planned for 11 October, with at least 10 people killed and more than 100 injured in the unrest. A round of talks mediated by the president of Senegal, Macky Sall, focused on returning power to the interim government while granting the putschists an amnesty in return. But the proposal was met with widespread scepticism before any draft was finalised.

Speaking to France’s RFI radio, Kafando had warned he had "serious reservations” about the proposal, adding that he had not been invited to the talks in Nigeria.

There were signs that people on the streets were also furious at the suggestion of an amnesty for the coup ringleaders. It was unclear early on Wednesday if the amnesty had made it into the deal signed between the coup leaders and the army.

On Tuesday, Burkina Faso’s military warned Diendéré it had the means to attack his elite forces. Diendéré hit back, saying his men would defend themselves if the army attacked them. "We do not want to fight but ultimately we will defend ourselves,” he said.

The president of the Ecowas commission, Kadré Désiré Ouédraogo, a former Burkinabe prime minister, said on Tuesday that military and humanitarian observers from member states would be sent to Burkina Faso "to monitor respect for human rights”.