Any efforts to tackle the crisis in Mali must focus on rebuilding a central state authority before trying to recapture northern desert zones now mainly in the hands of al Qaeda-linked Islamists, the International Crisis Group said.

Foreign powers should resist mounting pressure for a military operation to tackle the north as any such move underestimated the complexity of the situation and risked fomenting "terrorism" and ethnic conflict, the think tank warned in a report released on Wednesday.

Former colonial power France said last week that military intervention in Mali was "probable", and neighbour Niger has led African calls for swift action to prevent extremist groups, including al Qaeda and Nigeria's Boko Haram, from consolidating their positions across the Sahara-Sahel band, Reuters reports.

"It is urgent and necessary to restore the political, institutional and security foundations of the central state prior to working towards the north's reintegration into the republic," ICG said.

Mali, once seen as one of West Africa's most stable nations, has imploded since a March coup removed the country's president weeks before elections were due, a move that accelerated the fall of the north to a mix of secular and Islamist rebels.

The military has officially ceded power, but still meddles in politics, weakening an already fragile transitional government and complicating foreign efforts to rebuild the armed forces to reunite the country.

Having outgunned and outmanoeuvered their former secular allies, the north is now held mainly by Islamist groups, most notably Ansar Dine which is linked to al Qaeda and has imposed Islamic law in territories under its control.

"The prospects of a negotiated solution to the crisis are receding with the consolidation of hardline Islamist power in the north and a continued political, institutional and security vacuum in Bamako," ICG said.

"IGNORE CALLS FOR WAR"

West Africa's ECOWAS bloc has said for months it favours dialogue but is also readying a 3,000-strong force that could be dispatched to the country, though the planning and financing of any such mission remains unclear.

Mali's military looks no closer to returning to fight in the north and warnings the country may become "Africa's Afghanistan" have propelled the crisis up the international security agenda.

"Pressure is mounting in favour of an armed external intervention as specific security and political interests of foreign actors ... prevail over those of the Malian population in both the north and south," ICG said.

"It would be wise to ignore calls for war and continue with existing initiatives to promote a political settlement of the conflict without, however, neglecting security issues."

The Brussels-based group warned that military intervention could trigger inter-tribal score settling and rule out any chance of peaceful coexistence between communities.

Complicated ties and conflicting regional interests have long dogged Western efforts to improve cooperation in tackling the influence of groups linked to al Qaeda and international smuggling networks plying their trade in the Sahara.

The defeat of Libya's Muammar Gaddafi and looting of his arsenals during the Western-backed war flooded northern Mali with weapons and fighters, emboldening the loosely linked collection of rebels who launched their rebellion in January.

But ICG said Mali's grip on the north was already tenuous by then, having "rested on a loose network of personal, clientelistic, even mafia-style alliances with regional elites with reversible loyalties rather than on robust democratic institutions".