Peace talks between the Malian government and armed rebels opened on Monday in the Algerian capital, the second round of negotiations since July aimed at clinching a lasting peace agreement.

The Bamako government and six rebel groups, mostly Tuareg but also including Arab organisations, are seeking to resolve a decades-old conflict that created a power vacuum in the desert north that was exploited by Al-Qaeda.

A ceasefire has been in force since May when the rebels seized a large swathe of northern Mali in a major offensive.

Then in July, Bamako and the rebels met for a first round of talks in Algiers and signed a preliminary accord which set a roadmap for further negotiations.

"This time in Algiers, participants will get to the bottom of their problems and, it is to be hoped, come to an agreement," said former prime minister Modibo Keita, the Malian president's envoy at the talks.

Since President Ibrahim Boubacar Keita came to power negotiations have stalled, however, and northern Mali has seen a spike in violence by Islamist and separatist militants.

Riven by ethnic rivalries, a Tuareg rebellion and an Islamist insurgency in its vast desert north, the west African nation has struggled for stability and peace since a military coup in 2012.

Skirmishes in May between the Malian army and a coalition of rebels from the National Movement for the Liberation of Azawad (MNLA) and the High Council for the Unity of Azawad (HCUA) saw at least 50 soldiers killed in the Tuareg region of Kidal.

A ceasefire obtained by Mauritanian leader and African Union (AU) chief Mohamed Ould Abdel Aziz has been in place since, but the Malian government has expressed alarm at the "concentrations of armed groups" in the desert.

The talks are being held with a new defence agreement in place between Mali and its former colonial power France.

Paris recently wound up Operation Serval, its military offensive launched in January 2013 to oust Al-Qaeda-linked Islamists who had occupied northern Mali.