Dakar - Al-Qaeda's affiliate in North Africa is the militant organisation's richest faction and the dominant Islamist force among those controlling northern Mali, the head of the U.S. military's Africa Command (AFRICOM) said on Thursday.
General Carter Ham said the international community and the Malian government now faced a complex challenge to try to deal with the strengthened presence in Mali's largely desert north of al-Qaeda in the Islamic Maghreb (AQIM), the militant group's North African franchise.
Mali, for a long time seen as a stable nation in an often turbulent West African region, imploded in the space of a few weeks after a March 22 coup sowed confusion and allowed a mix of Tuareg separatists and Islamist rebels to occupy the northern two-thirds of the country.
Over recent weeks, the Islamists, including AQIM fighters, have gained control of the vast area, creating what African and Western leaders are calling a "terrorist haven" that they say threatens both regional and international security.
African leaders and Western governments including the United States and France, the former colonial power in the region, have been discussing the idea of a Western-backed African military intervention force going in to try to expel the rebels from the north and reunite divided Mali.
Ham said the groups now controlling Mali's north were boosted by the spillover of arms and fighters from Libya's conflict last year. But he criticised as "ineffective" previous efforts to tackle AQIM in northern Mali, where its members have held kidnapped foreigners for multi-million-dollar ransoms.
"We - the international community, the Malian government - missed an opportunity to deal with AQIM when they were weak. Now the situation is much more difficult and it will take greater effort by the international community and certainly by a new Malian government," Ham told reporters in Senegal.
The U.S. general said relationships between the various Islamist groups in northern Mali were complex and that it was not clear if they were aligned on an ideological or a purely opportunistic basis.
"We believe the most dominant organisation is AQIM. We think they are al-Qaeda's best funded, wealthiest affiliate," he said.
"AQIM gained strength, they gained a lot of money through kidnapping for ransoms and they became a stronger and stronger organisation," he added.
The U.N. Security Council on July 5 endorsed West African efforts to end unrest in Mali but has stopped short of backing military intervention, asking for a more detailed plan for such an operation. Experts from the African Union and the West African regional grouping ECOWAS have been working on this plan.
Mali's interim president Dioncounda Traore, who has spent weeks abroad after he was attacked by pro-coup mobs in May, will return to Bamako on Friday and try to form a new government by the end of the month, his party said.
Tens of thousands displaced
Asked about reports that the Islamists in northern Mali include fighters from Afghanistan and Pakistan, Ham said he did not have independent confirmation of this. However, he estimated the numbers of foreign fighters in the north in the "dozens and perhaps in the low hundreds".
AQIM emerged out of Algeria's civil conflict but it has gradually expanded south into the Sahara and has raised its profile in recent years, partly through hit-and-run attacks on regional armies but mainly by kidnapping Westerners for ransom.
Security experts say the group's mainly Algerian leadership has forged strong bonds with northern Malian communities and criminal networks trafficking in arms, drugs and migrants.
Ham repeated U.S. offers to broadly assist regional efforts to try to resolve Mali's crisis, which has displaced around 420,000 people, according to the U.N. Office for the Coordination of Humanitarian Affairs (OCHA).
But he said putting U.S. troops on the ground could be counter-productive and refused to comment on the possibility of Washington using drones for air strikes similar to those carried out on militant targets in Yemen or Pakistan.