Mali on edge after suicide attack

Residents of a village near Gao, the largest city in the north, said they had detained two young men, an Arab and a Tuareg, whom they claimed were wearing explosive-rigged belts and travelling on the same road where the suicide bombing on Friday wounded a soldier at a checkpoint.

In Timbuktu, a grave was discovered Friday containing several bodies including those of three Arab shopkeepers who had recently been arrested by the Malian army, the independent Mauritanian news site ANI reported.

Northern Mali is being torn by rising tensions between light-skinned Arabs and Tuaregs -- often accused of supporting the rebel occupiers who seized control of the north for 10 months -- and their black neighbours.

Rights groups have accused the Malian army of summary executions of Tuareg and Arabs and called on the government to protect them from reprisal attacks.

Troops in Gao were fortifying checkpoints with sandbags and heavy machine guns and patrolling the city in heavy rotation after Friday's suicide blast, carried out by a young Tuareg who rode a motorcycle up to a checkpoint and detonated an explosive belt.

The Movement for Oneness and Jihad in West Africa (MUJAO) claimed the attack and vowed to carry out more against "the Malian soldiers who chose the side of the miscreants, the enemies of Islam".

MUJAO is one of a trio of Islamist groups that seized northern Mali before France sent in fighter jets, attack helicopters and 4,000 troops to drive them out.

The French-led operation, launched on January 11 as the insurgents advanced toward the capital Bamako, has succeeded in forcing the Islamists from the towns under their control.

But they are thought to retain a presence in the vast desert spaces of the country's north, and France is now anxious to hand over the operation to UN peacekeepers amid fears of a prolonged insurgency.

In Bamako, heavily armed Malian soldiers surrounded a base housing rival paratroopers where a firefight the day before killed two adolescents and wounded another 13 people.

The clash between the rival units highlighted the deep divisions in the Malian military.

The paratroopers are loyal to ex-president Amadou Toumani Toure, ousted in a March 2012 coup, and were protesting an order absorbing them into other units to be sent to the frontline.

The nation imploded last year after the coup, waged by soldiers who blamed the government for the army's humiliation by a rebellion among the Tuareg, a north African people who have long complained of being marginalised by Bamako.

A month later, paratroopers launched a failed counter-coup that left 20 people dead.