BAMAKO - West African heads of state will meet in Abuja on Sunday to adopt a plan for their troops to recapture northern Mali from radical Islamists, the grouping said in a statement on Thursday.

Once approved by the Economic Community of West African States (ECOWAS) leaders, the strategy "will then be transmitted through the African Union, before November 15, to the UN Security Council."

The Security Council on October 12 approved a resolution urging ECOWAS to speed up preparations for a military intervention to help recapture northern Mali. It gave ECOWAS until November 26 to clarify its plans.

ECOWAS army chiefs on Tuesday adopted the military blueprint, which was drawn up with the help of experts from the European Union, AU, UN and the region.

The details of the plan have not been made public, but delegates say over 4,000 troops could be sent into Mali, whose vast arid north has been occupied by Al Qaeda-linked extremists for seven months.

The UN wants clarification on the composition of the proposed force, the level of participation from the various West African nations, the financing of the operation and the military means to carry it out.

The ECOWAS statement said the bloc's military brass has asked for a planning committee to be set up to "refine the harmonised plan" and organise a donors conference.

This committee will be charged with "identifying the shortfalls as soon as possible and proposing the types and number of units" which will make up the force.

The Security Council is expected to adopt a resolution giving the green light for the deployment of troops once it has studied the intervention plan.

Mali, once one of the region's most stable democracies, rapidly imploded after a coup in March allowed Tuareg desert nomads, who had relaunched a decades-old rebellion for independence, to seize the main towns in the north with the help of Islamist allies.

The secular separatists were quickly sidelined by the Islamists who had little interest in their aspirations for an independent homeland and set about implementing their version of strict sharia law.

Ansar Dine (Defenders of Faith) and the Movement for Oneness and Jihad in West Africa (MUJAO) have cracked down on local populations, stoning unmarried couples, amputating thieves' hands and whipping drinkers and smokers.

The crisis has displaced about 200,000 Malians inside the country, while as many have fled to neighbouring states, according to the UN.

Facing a potentially violent ouster, Ansar Dine has sent envoys to Ouagadougou and Algiers for negotiations and this week called for all armed movements to halt hostilities and join in dialogue, while rejecting "all forms of terrorism".

The Islamists' ties with Al-Qaeda in the Islamic Maghreb (AQIM) which has long been present in Mali's north, has triggered fears in the region and the west that the zone could become a haven for radicals.

Ansar Dine spokesman Mohamed Ag Aharid on Wednesday warned in Ouagadougou that any military intervention in Mali would "set the region ablaze."