Insurgency-hit Mali has freed over 100 alleged or convicted jihadists to secure the release of a top politician and a French charity worker, sources close to the talks said Monday.

This is a rare mass release of prisoners in the fragile West African country, which is struggling with an eight-year-old Islamist insurgency that has claimed thousands of lives.

Soumaila Cisse, a former opposition leader and three-time presidential candidate, was abducted on March 25 while campaigning in his home region of Niafounke ahead of legislative elections.

Sophie Petronin was abducted in 2016
Sophie Petronin was abducted in 2016 SITE INTELLIGENCE GROUP / -

Sophie Petronin, a French charity worker, was abducted by gunmen on December 24, 2016, in the northern city of Gao. She is presently the last French national held hostage in the world.

The last video in which Petronin appeared was received in June 2018. She seemed tired and emaciated, and appealed to French President Emmanuel Macron.

In another video, in November 2018, in which she did not appear, her kidnappers said her health had deteriorated.

"As part of the negotiations to obtain the release of Soumaila Cisse and Sophie Petronin, more than one hundred jihadist prisoners were released this weekend," one of those in charge of the negotiations, who asked not to be named, told AFP.

A picture taken in July shows a banner reading "Free the Honorable Soumaila Cisse ! When is soon ?"
A picture taken in July shows a banner reading "Free the Honorable Soumaila Cisse ! When is soon ?" AFP / MICHELE CATTANI

An official at the security services confirmed the information.

The prisoners were released in the central region of Niono and in Tessalit in the north after arriving by plane, the official said.

A lawmaker in Tessalit, who also requested anonymity, confirmed to AFP that "large numbers of jihadist prisoners" arrived there on Sunday.

Malian authorities suspect that an Al-Qaeda-linked group, led by Amadou Koufa and active in the country's centre, staged the kidnappings.

Swathes of the sprawling country remain outside government control
Swathes of the sprawling country remain outside government control AFP / STRINGER

The release came with an interim government due to govern Mali for 18 months before staging elections after a military junta overthrew president Ibrahim Boubacar Keita in August.

The kidnapping of former opposition leader Cisse was one of the factors that fuelled popular protests which led to the ouster of Keita over his perceived inability to tackle jihadists and Islamist insurgency.

Despite naming a civilian leader to head the transition -- something the junta agreed to after sustained international pressure -- the military will have a large say in the running of the interim government.

Landlocked Mali's neighbours have taken a hard line with the junta, fearful that the fragile nation of some 19 million people could spiral into chaos.

Swathes of the vast and arid nation already lie outside of government control, due to a lethal jihadist insurgency that first emerged in 2012.

The insurgency has also inflamed ethnic tensions.

Keita had officially opposed negotiations with jihadist groups but his government launched talks with some of them in February.

Covert negotiations are on for the liberation of some hostages and for a ceasefire, according to sources.

The military junta has not closed the door to negotiations with jihadists and has also vowed to secure Cisse's release.

Mali's former colonial ruler France has 5,100 soldiers deployed across the Sahel region as part of its anti-jihadist Operation Barkhane.