We know that international politics and countering insurgency / terrorism can make for unlikely allies and situations - so with that caveat aside:
The Islamist ‘terrorist’ groups that have taken over control of northern Mali are not only the creations of Algeria’s secret police, the Département du Renseignement et de la Sécurité (DRS), but they are being supplied, supported and orchestrated by the DRS.
Link:http://www.opendemocracy.net/jeremy-...-northern-mali

To be frank the byzantine intrigues involved make me sceptical, but we do know that the Algerian insurgency was "dirty", so this reference may support the argument:
.. John Schindler on July 10 (2012). In an article in The National Interest entitled ‘The Ugly truth about Algeria’, Schindler, a former high-ranking US intelligence officer and long-standing member of the US National Security Council (NSC) and currently Professor of National Security Affairs at the US Naval War College, ‘blew the whistle’ on Algeria when he described how:

“the GIA (Armed Islamic Group) [of the 1990s] was the creation of the DRS; using proven Soviet methods of penetration and provocation, the agency assembled it to discredit the extremists. Much of GIA’s leadership consisted of DRS agents, who drove the group into the dead end of mass murder, a ruthless tactic that thoroughly discredited GIA Islamists among nearly all Algerians. Most of its major operations were the handiwork of the DRS, including the 1995 wave of bombings in France. Some of the most notorious massacres of civilians were perpetrated by military special units masquerading as mujahidin, or by GIA squads under DRS control.”
Sending Algerian SF into mali to protect AQIM is too hard to accept.