African troops expected

More than two decades of peaceful elections had earned Mali a reputation as a bulwark of democracy, but that image unravelled in a matter of weeks after a military coup last March that left a power vacuum for the Islamist rebellion.

French President Francois Hollande's intervention in Mali has won plaudits from leaders in Europe, Africa and the United States, but it is not without risks.

It raised the risk level for eight French hostages held by al Qaeda allies in the Sahara and for the 30,000 French expatriates living in neighbouring, mostly Muslim states.

Concerned about reprisals, France has tightened security at public buildings and on public transport. It advised its 6,000 citizens in Mali to leave as spokesmen for the Islamist groups have promised to exact revenge.

In its first casualty of the campaign, Paris said a French pilot was killed on Friday when rebels shot down his helicopter.

Hours earlier, a French intelligence officer held hostage in Somalia by al Shabaab extremists linked to al Qaeda was killed in a botched commando raid to free him.

President Hollande says France's aim is simply to support a mission by West African bloc ECOWAS to retake the north, as mandated by a U.N. Security Council resolution in December.

With Paris pressing West African nations to send their troops quickly, Ivory Coast President Alassane Ouattara, who holds the rotating ECOWAS chairmanship, kick-started the operation to deploy 3,300 African soldiers.

Ouattara, installed in power with French military backing in 2011, convened a summit of the 15-nation bloc for Saturday in Ivory Coast to discuss the mission.

"The troops will start arriving in Bamako today and tomorrow," said Ali Coulibaly, Ivory Coast's African Integration Minister. "They will be convoyed to the front."

Military analysts expressed doubt, however, that African nations would be able to mount a swift operation to retake north Mali - a harsh, sparsely populated terrain the size of France - as neither the equipment nor ground troops were prepared.

The United States is considering sending a small number of unarmed surveillance drones to Mali as well as providing logistics support, a U.S. official told Reuters. Britain and Canada have also promised logistical support.

Former French colonies Senegal, Niger and Burkina Faso have all pledged to deploy 500 troops within days. In contrast, regional powerhouse Nigeria, due to lead the ECOWAS force, has suggested it would take time to train and equip the troops.