LONDON: African troops trying to flush out al-Qaeda fighters in northern Mali have fought a major battle with Islamists holed up in a remote mountain range in the Sahara Desert.
Thirteen Chadian soldiers and 65 fighters linked to al-Qaeda were killed during the clashes in the Adrar des Ifoghas mountains near the Algerian border, where French special forces are also searching for Islamist bases.
The battle was the bloodiest since the Malian leader, Amadou Sanogo, asked French troops to intervene in the country a month ago, amid fears it was becoming an al-Qaeda safe haven.
The response from the Islamists suggests they are far from a spent force. A Chadian military source said on Saturday its forces had attacked a rebel base that appeared to be of ''significant importance''.
The President of France, Francois Hollande, confirmed French troops had also been in the Adrar area, in a ''last phase'' of the campaign against Al-Qaeda in the Islamic Maghreb.
Troops from neighbouring African nations - including 2000 Chadians - are meant to take over leadership of the operation when France begins to withdraw forces from its former colony next month.
After driving Islamists from towns such as Gao and Timbuktu, France and its African allies have focused on the remote north-east mountains and desert, an area the size of France, which includes networks of caves, passes and porous borders.
They believe some of the eight French hostages held by groups linked to al-Qaeda are being kept in the area.
Fresh fighting has also erupted in northern Mali between ethnic Tuaregs and an unidentified armed group.
Tuaregs of the Azawad National Liberation Movement (MNLA) were fighting on Saturday what one source said ''seemed to be Arab fighters'' near the northern town of Tessalit, where suicide car bombers killed three people a day earlier.
Al-Qaeda-linked Islamist rebel group the Movement for Oneness and Jihad in West Africa (MUJAO) has claimed responsibility for the bombings in In Khalil, near Tessalit, saying they were specifically targeting the MNLA, which has been co-operating with French forces.
On Thursday, the MUJAO also claimed an attack in the northern city of Kidal, in which a vehicle exploded near a camp occupied by French and Chadian troops.
The mountainous region between Tessalit and Kidal is strategically important, seen as a stronghold for many Tuaregs and used by Islamists as a hideout from French forces.
In Saturday's statement, a MUJAO spokesman, Adnan Abu Walid Sahraoui, warned future suicide attacks were planned in the Malian capital, Bamako, as well as in the capitals of Burkina Faso and Niger, whose troops are part of the African force in Mali.
''Bamako, Ouagadougou and Niamey remain favourable zones for our suicide bombers, who are ready to make the planned attacks,'' he said.
He demanded the groups holding French hostages in the Sahel region and in Niger kill them in revenge against France, which he accused of ''staging a crusade against Islam and Muslims''.
Telegraph, London; Agence France-Presse