Bamako - A car bomb exploded in the remote northern Malian town of Kidal on Tuesday, Mali's army said, the second attack there in less than a week as Islamist rebels step up a guerrilla campaign.

French forces have been stationed in Kidal since driving out al-Qaeda-linked fighters late last month as part of an intervention against the Islamist militants who had seized the northern two-thirds of the West African country.

Malian army spokesperson Modibo Nama Traore said a car bomb had exploded in the town, which lies close to the Adrar des Ifoghas mountains where the Islamists fighters are still battling French and Chadian forces.

Members of the MNLA Tuareg insurgent group, which returned to its traditional stronghold of Kidal after the Islamists fled, said the car bomb exploded at one of their checkpoints at the south-east entrance to the town, killing at least four people.

A Malian intelligence source said three other vehicles had been destroyed in the attack. - Reuters