At least 10 civilians and one soldier were killed in northern Mali on Thursday when their vehicles hit landmines planted by suspected Tuareg rebels, Malian military officers said.

The casualties in the north of the Sahel state followed three attacks this week by the Malian rebels in the desolate mountain region near the border with Algeria and Niger.

The civilians were killed, and several were injured, when their vehicle set off a mine laid by the Tuareg fighters as they pulled back following their raids in the Tin-Zaouatene area, military spokesman Colonel Abdoulaye Traore said.

In a separate incident, a Malian soldier was killed and several were hurt when their vehicle hit a second mine, another officer, who asked not to be identified, said.

Late on Wednesday, the marauding rebels ambushed a military patrol in the same area, leaving several soldiers missing and seizing five vehicles, in their third major attack this week in the landlocked West African state.

In two similar attacks earlier this week, 38 soldiers were taken hostage.

Another military patrol was able to recover nine of those prisoners earlier on Wednesday when they were abandoned by a group of armed men who fled toward the border with Niger.

In a seven-month uprising in Niger, Tuareg-led rebels have killed more than 45 soldiers, and officials in the two countries see links between the desert attacks.

Wednesday's late night ambush in Mali was one of the worst to date, the military sources said.

"It is a heavy toll: five Toyota pick-ups taken, others burned or disappeared, dozens of soldiers scattered and many missing, including a lieutenant who may have been captured," said one military source, who asked not to be identified.

SECURITY TALKS

The area is regarded as a stronghold of Tuareg leader Ibrahima Bahanga, whom Malian authorities accuse of killing a gendarme in an attack in May backed by rebels from the Niger Movement for Justice (MNJ).

Bahanga, one of the leaders of a previous Tuareg revolt which won greater autonomy for the light-skinned tribesmen in Mali and Niger, has been disowned by a broader Malian rebel alliance which signed a peace deal with President Amadou Toumani Toure in July 2006.

Toure has called for a regional conference on security in the Sahel.

Niger President Mamadou Tandja recently sent delegations to Algeria, Libya and Sudan to appeal for support in ending violence, which his government has dismissed as banditry.

Last week, Mali and Niger's security ministers met in the eastern Malian town of Gao to sign a deal allowing each others' security forces to pursue suspected bandits across their border.

The MNJ, which demands greater Tuareg control over revenues from uranium mining in the desert north, has publicly denied any links with the violence in Mali.

Niger this week banned discussion of the violence on live television. The government expelled a Libyan diplomat from Agadez this month for interference in Niger's internal affairs, after alleging that some foreign powers are backing the rebels.

The sparsely-populated Agadez region, where the insurgency is raging, is the size of France and difficult to police. The government declared a state of emergency there last week.