Chad's parliament voted overwhelmingly Monday for a gradual withdrawal of troops from Mali where 36 have died in a French-led campaign to oust armed Islamists from the north of the country.

Lawmakers were nearly unanimous in asking government to withdraw its 2,250 troops "within a reasonable timeframe".

A suicide bomber killed at least three Chadian soldiers in Mali Friday, military sources said, in a deadly demonstration of the troubled nation's ongoing security crisis days after France began withdrawing its troops.

The soldiers were shopping in the northern city of Kidal when an Islamist bomber struck, according to Malian and Chadian sources who gave a provisional toll of three soldiers killed and four wounded.

Some 74,000 Malians, who have been displaced by war and ethnic tensions, are in need of urgent help in the desert of Mauritania, the Doctors without Borders (MSF) aid group said Friday.

In the Mbera camp "humanitarian assistance is insufficient," said the group in a report.

As France begins withdrawing its troops from Mali, a top U.S. defense official has said a U.N.-mandated African force was "incapable" of taking over the battle against Islamist extremists.

Paris, which sent 4,000 troops to Mali in January to block a feared advance on the capital Bamako by Islamist fighters, said Tuesday it had pulled out its first batch of soldiers preparing to hand over to an African force of 6,300 in the coming weeks.

France has withdrawn its first batch of soldiers from Mali, the army said Tuesday, as it begins to pull out troops sent to battle Islamist fighters in the west African nation.

The military's chief of staff said around 100 soldiers had been withdrawn and sent to Paphos in Cyprus, where they will spend three days in a hotel before heading back to France.

A French force of 1,000 soldiers in a major offensive has swept a valley thought to be a logistics base for al-Qaida-linked Islamists near the Malian city of Gao, an Agence France Presse journalist accompanying the mission reported.

Operation Gustav, one of France's largest actions since its intervention in its former colony, involves dozens of tanks, helicopters and aircraft, said General Bernard Barrera, commander of the French land forces in Mali, on Monday.

The French foreign minister reassured Mali on Friday that France was not planning an "overnight" withdrawal of the troops it sent to liberate the west African nation from al-Qaida-linked rebels.

Laurent Fabius, in Bamako to discuss the pullout scheduled for the end of April, said France would provide a permanent "support force" of 1,000 French soldiers after elections that the deeply-divided country has promised for July.

At least three Islamists were killed in Timbuktu on Monday during a sweep by French and Malian soldiers after a deadly weekend battle in the fabled Saharan city, a military source said.

"During our clean-up operation, the Mali and French armies destroyed a public building in the center of town where the terrorists were hiding. We have found the bodies of three terrorists," the Malian military source told Agence France Presse.

Malian troops swept Timbuktu for remaining Islamist fighters after a weekend battle that left seven dead and forced France to dispatch reinforcements and fighter jets to help Mali's army.

By late Sunday relative calm had been restored, after Islamist militants used the chaos created by a suicide bombing Saturday night to infiltrate the city and engage French and Malian troops in a day-long battle that left four more rebels, a soldier and a civilian dead.

Malian troops backed by French forces on Sunday clashed with Islamist fighters who had infiltrated the northern city of Timbuktu, leaving two jihadists dead and four Malian soldiers wounded, a Malian army officer said.

"Jihadists have infiltrated the center of Timbuktu... Our men are currently fighting them with the support of a unit of our French partner," the Malian officer told Agence France Presse by telephone.