Burkina Faso's interim President Michel Kafando officially resumed power Wednesday after a week-long coup by renegade troops, whose leader conceded the enterprise had been a "mistake" lacking popular support.

"The coup is over," the putschists' leader General Gilbert Diendere said as he and his backers bowed to pressure from regional powers and former colonial ruler France.

"Carrying out this coup was the biggest mistake," he acknowledged hours after Kafando resumed office.

"We knew the people were not in favour of it. That is why we have given up."

The move came after marathon talks brokered by the ECOWAS west African regional bloc in bid to restore calm to a country in transition following 27 years of iron-fisted rule by Blaise Compaore, who was ousted as president last October and fled the country.

The European Union, which had joined an international chorus of condemnation of the coup, welcomed Kafando's re-instatement.

"President Kafando's return to his duties and the announced return to the transition process amount to crucial steps for normalising the situation in Burkina Faso," the EU said in a statement.

Kafando, who has led the landlocked west African country since the anti-Compaore uprising, said his "main objective" now was to organise a vote.

Before the crisis, presidential and legislative elections had been slated for October 11.

Although an election would take place, it would have to be put back by "several weeks", said Prime Minister Isaac Zida, citing technical reasons.

The coup and the resulting unrest claimed the lives of at least 10 people while more than 100 were wounded.

Zida said the RSP, the elite presidential guard which staged the coup, would now have to be reconstituted as it was "practically unimaginable" to retain the body in its current format.

At a ceremony attended by African heads of state in the capital Ouagadougou, Kafando said he was open to dialogue on all sides and that "going to the polls is still the main objective."

- 'Our cause is just' -

"We remain determined to pursue the sacred mission that the people of Burkina Faso have given us: to put in place credible, trustworthy institutions for a new Burkina that we have decided to build, in true democracy and justice," the restored leader said.

Among dignitaries attending the ceremony were Benin President Thomas Boni Yayi, Ghana President John Dramani Mahama, Niger counterpart Mahamadou Issoufou and Nigerian vice-president Yemi Osinbajo.

In all, six ECOWAS heads of state travelled to Ouagadougou to oversee Kafando's formal re-installation and to try and resolve two contentious issues: an amnesty for the putschists and whether upcoming elections should be open to supporters of Compaore.

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

Under the terms of the deal which ended the crisis, the RSP agreed to stand down from their positions in Ouagadougou, while the army also agreed to pull out, while guaranteeing the safety of RSP members and their families.

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

The crisis erupted last Wednesday when RSP guards detained the interim leaders who had been running the country since Compaore's overthrow.

The elite unit of 1,300 men officially declared a coup Thursday and installed rebel leader Diendere, Compaore's former chief of staff, as the country's new leader.

The coup triggered immediate protests that led to deadly clashes between protesters and RSP troops. The coup leaders also came under enormous regional and international pressure, with former colonial ruler France threatening sanctions if they did not hand back power.

On Tuesday, army chiefs ramped up the rhetoric by urging Diendere and his troops to surrender or risk an armed confrontation with anti-coup soldiers.

Talks by west African mediators this week, including ECOWAS chairman and Senegalese President Macky Sall, focused on returning the interim government to power while granting the putschists an amnesty.

They also proposed allowing Compaore loyalists to run for office in the upcoming vote -- after they complained of being barred in the planned October polls.