France said Thursday its warplanes had hit Islamist command posts near the last militant stronghold in northern Mali, as the UN mulled a peacekeeping force to take over the fast-moving French-led operation.

Ground troops gathered at the gates of Kidal, a desert outpost that is the last rebel stronghold yet to be fully recaptured, as France said its fighter jets had blasted command centres, training camps and depots run by Islamist extremists in the mountains north of the town.

Many rebels are believed to have slipped into the desert hills around Kidal since France launched air strikes on January 11 in a surprise assault to block an advance towards the capital, Bamako, by Al Qaeda-linked extremists who have occupied the north for 10 months.

The latest air strikes were carried out over the past few days in the Aguelhok region near the border with Algeria, a French military spokesman told journalists.

To back up the ground troops already in place, a column of 1,400 Chadian soldiers was heading by road towards Kidal from the Niger border, he added.

Defence Minister Jean-Yves Le Drian said France's air attacks had hit the rebels hard.

"The jihadists suffered heavy losses," Le Drian said. "There were numerous strikes which hit their equipment and men.

But, in a sign the insurgents remain a threat, at least two Malian soldiers were killed when their vehicle drove over a landmine in central territory recaptured last week from the rebels, a security source said.

Paris has urged dialogue between "non-armed terrorist groups" and Mali's interim government for a long-term solution to the woes of the country, which straddles the Sahara desert and the region to the south known as the Sahel.

Tuareg desert nomads in the north have long felt marginalised by Bamako, and last January rebels launched the latest in a string of insurgencies, kickstarting Mali's rapid implosion.

The Tuareg National Movement for the Liberation of Azawad (MNLA), which had allied with Islamist groups, rapidly overran the vast desert north.

They were soon thrust aside by the extremists, who imposed a brutal form of Islamic law on areas under their control, where offenders were punished by public whippings, amputations and executions.

Interim president Dioncounda Traore said Thursday he was willing to talk to the secular Tuaregs from the MNLA, but would not meet any of the Islamist groups.

His comments came after a breakaway rebel faction, the Islamic Movement of Azawad (MIA), said it rejected "extremism and terrorism" and appealed to the international community to prevent the deployment of Malian and West African troops in its base, Kidal, 1,500 kilometres (930 miles) northeast of Bamako.

But Traore dismissed the apparent MIA olive branch, saying: "Because fear has now changed sides, they are looking for a way out."

And the Malian army said it already had a reconnaissance unit in the town to prepare the way for more troops.

-- Alarm over abuses --

France, Mali's former colonial ruler, is keen to hand over its military operation to nearly 8,000 African troops slowly being deployed.

UN officials said planning was at an advanced stage to gather those forces together under the umbrella of a formal UN peacekeeping operation.

France now has 3,500 troops on the ground and with support from the Mali army, has retaken several rebel strongholds, including the large regional town of Gao and the fabled desert trading post of Timbuktu, with no resistance.

With the Islamists on the run, rights groups have voiced fears of widespread abuses and reprisals against Tuaregs and Arabs accused of supporting them, after reports of summary executions by Malian troops.

"All sides have committed very serious violations, and we believe that they should be investigated," said Human Rights Watch's Africa director, Tiseke Kasambala.

The European Union also joined the United States and France in raising alarm over the threat of reprisal attacks against minorities.

Adding to the list of threats to the region's stability, ex-UN chief Kofi Annan said there was evidence the crisis in Mali was driven by dangerous alliances between drug smugglers, criminal gangs and extremist groups operating across the region's porous borders.

"These developments threaten the stability of our region as we have witnessed so graphically in Mali in recent weeks," he said.

That assessment was echoed by Chadian President Idriss Deby, who said "narco-terrorists" also had their sights on Chad, Niger and Burkina Faso.

Chad has led African troop pledges with 2,300 promised for Mali, whose interim president met with Deby Thursday and thanked him for the support.

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