Mali's government and several armed groups signed a peace accord Friday in a ceremony attended by numerous heads-of-state but missing the crucial backing of the main Tuareg-led rebel groups.

The Coordination of Azawad Movements (CMA) had provisionally initialled the document a day earlier but is demanding concessions and its three principal factions did not attend the rubber-stamping ceremony in the Malian capital Bamako.

The so-called "Algiers Accord" aims to bring stability to the north, the cradle of several Tuareg uprisings since the 1960s and a stronghold for al-Qaeda-linked jihadists who have been regrouping since they were ousted by the French in 2013.

It was signed by Malian Foreign Minister Abdoulaye Diop, three representatives of pro-Bamako militias and two minor members of the CMA rebellion, as well as a team of mediators led by Algeria.

The international community has been increasing pressure on the CMA to get on board the peace process as a means of isolating the jihadists, particularly since an Islamist attack on March 7 in Bamako in which two Europeans died.

Zimbabwean President Robert Mugabe, who chairs the African Union, attended along with around 20 heads of government and state from across the region and numerous other dignitaries.

The televised ceremony -- which follows months of UN-backed negotiations -- went ahead against the odds amid repeated recent violations of a ceasefire deal agreed between the army and various pro-government and rebel militias.

But it risked being largely devoid of substance without the signatures of the Tuareg-dominated National Movement for the Liberation of Azawad (MNLA) and High Council for the Unity of Azawad. The Arab Movement of Azawad (MAA) was also absent.

- 'Important step' -

"Today is a very important step. It's true we would have liked the presence of everyone, but it is important that the process moves forward," said French development minister Annick Girardin

"The development of Mali can only be achieved in peace. Without peace, there can be no development. And France, Mali's friend, will always be at its side to achieve this."

Observers had said the international community could consider the ceremony a partial success if it persuaded at least some rebel groups within the CMA to sign the accord.

The alliance had been expected to present a united front but, to the surprise of many at the ceremony, two representatives of minor CMA groups took part.

One of them, Mohamed Ousmane Ag Mohamedoun of the Coalition of People of Azawad, was suspended after the ceremony, his group announced.

Federica Mogherini, the chief diplomat of the European Union, had earlier downplayed the absence of the most important rebel groups, arguing that the signature "by most stakeholders is a decisive step".

"Initialling is a sign of good faith to move towards a final, comprehensive and lasting solution but further adjustments are needed before signing," rebel representative Almou Ag Mohamed said in Algiers on Thursday, explaining the CMA's decision to boycott Friday's ceremony.

Another CMA leader, Sidi Brahim Oud Sidat, said there would be further negotiations on the alliance's political and security demands.

"Once these requests are met, we will sign the agreement," he said.

- Red line -

Mali was shaken by a coup in 2012 which cleared the way for Tuareg separatists to seize the towns and cities of the vast northern desert.

Militants linked to Al-Qaeda then overpowered the Tuareg to take control of northern Mali for nearly 10 months, imposing a brutal interpretation of Islamic law with punitive amputations and executions.

A French-led military offensive ousted the militants but the country remains deeply divided, with the Tuareg and Arab populations of the north accusing sub-Saharan ethnic groups in the more prosperous south of marginalising them.

Northern Mali has seen an upsurge in attacks by pro-government militias and various factions of the Tuareg-led rebellion, leaving many dead on both sides.

The Algiers Accord calls for the creation of elected regional assemblies but not autonomy or federalism, in deference to the concerns of the government about separatism.

The CMA has said it will not accept a deal without an amendment recognising "Azawad", the name used by the Tuareg for the northern part of Mali, as a "geographic, political and juridical entity".

Yvan Guichaoua, a lecturer at the University of East Anglia in Britain and an expert on the Sahel region, said the mediation team had been too keen to impose its own constraints on the talks.

He criticised its requirement "that the participants align with its anti-terrorist agenda in a bid to draw a red line between the reputable armed movements and the pariah armed movements".

"This May 15 is not a very glorious day but nothing prevents further work," he told AFP.