And MUJAO says it has planted mines around the northern towns it controlled. One has already killed four Malian soldiers. The group's spokesman, Walid Abou Sarraoui, told Radio France Internationale Thursday that the jihadists were "opening a new zone of conflict."
In Gao, a town controlled by MUJAO until recently, a suicide bomber on a motorcycle blew himself up Friday, injuring one other person.
The Intelligence Challenge
Northern Mali is larger in area than Spain and while much is open desert, the Adrar de Ifoghas mountains include networks of caves and passes. Moktar Belmoktar, whose followers carried out the attack on the Algerian gas facility at In Amenas in January, and Iyad ag Ghali -- a Tuareg and leader of Ansar Dine -- know this region in intimate detail.
Over the years, Belmoktar (who is Algerian) has used his knowledge of the region to establish a flourishing smuggling and kidnapping business that has funded weapons-buying and recruitment. His group and MUJAO are thought to have taken seven French hostages they already held into the impenetrable Ifoghas.
French intervention may have disrupted traditional smuggling routes -- depriving these groups of revenues. But the idea that the Islamists will wither away is wishful thinking, according to regional analysts. Hence the recent agreement made by the U.S. to begin stationing surveillance drones in neighboring Niger. France has virtually no drone capability of its own.
The question is, as the French withdraw, whether the African garrison force replacing them has the resources to go after the remnants of these groups. Perhaps implicitly acknowledging its limitations, France has already suggested a U.N. peacekeeping force to be deployed by April.
U.N. Secretary-General Ban Ki Moon is apprehensive. "Our worry is that [the jihadists] could reappear, and that could affect the countries of the region," he said Thursday.
Distrust and Revenge
The events of the last year in Mali have introduced an atmosphere of deep distrust -- and episodes of revenge -- into what had been a moderate and tolerant country. Tuareg stranded in the capital Bamako speak of hostility toward them.
The Malian army is accused of atrocities in towns that have been recaptured. In one incident, troops are said to have killed a group of Malian and Mauritanian preachers on a bus in Diabaly in September; it's unclear whether they mistook them for militants.
The International Federation of Human Rights Leagues said last week that Malian soldiers had summarily executed at least 11 people in Sevare. The U.N. refugee agency says reports of revenge attacks against Tuareg and Arabs are dissuading some among the nearly 400,000 internally displaced from returning home.
In turn Malian officials have accused the MNLA -- the largest Tuareg rebel group -- of executing soldiers.
Despite years of training by U.S. Special Forces, discipline in the Malian army fell apart after Tuareg separatists began seizing parts of northern Mali a year ago. Tuareg army units (integrated into the military in the 1990s) defected.
This sense of distrust is complicated by facts on the ground. Rather than the Malian authorities taking control of cities like Kidal in the wake of the French advance, it is Tuareg separatists of the MNLA (who defeated the army last year) that are patrolling the streets. That sets up another possible confrontation between troops and separatists.
Mali's small but influential Arab population may also be targeted for revenge because some of the more ruthless Islamist militants were Arabs (though not all were from Mali) associated with the implementation of Sharia law.
Talking to the Tuareg
The grievances among the ethnic Tuareg that led to the division of Mali in the first place are yet to be addressed. The on-off alliance of Tuareg and Islamist groups appears to have hardened resentment toward the north among southerners.
The press in Bamako has voiced visceral hostility toward the MNLA for its attempts to assist the French in pursuit of militants of Ansar Dine. The MNLA "is and remains the main cause of unhappiness in northern Mali," complained the newspaper MaliJet. "Sooner or later, history will catch up with it."
Another journal noted it was now the turn of the Tuareg, who had "invited the terrorists into the north" along with France to "install another republic or another province of France in the heart of the Sahel."