A suicide bomber killed at least six people after ramming his explosives-laden vehicle into a checkpoint in the northern Malian city of Kidal, military and hospital sources said. The attacker struck a checkpost manned by Tuareg separatists supporting the French-led military offensive against Islamist insurgents. "The suicide attack targeted the checkpoint on the eastern side of Kidal which is manned by the MNLA (National Movement for the Liberation of Azawad)," a French military official told AFP in Gao, the main city in the north. A hospital source told AFP there were seven dead including the bomber, with another 11 wounded. Several other officials confirmed the blast was an attack following an initial report that it may have been a controlled explosion of ammunition seized from the Islamist insurgency. The Islamic Movement for Azawad (MIA), another armed group, said its fighters were also on duty at the targeted checkpoint. "Suicide attackers did this," Alghabass Ag Intalla, whose group is a moderate splinter of the Al-Qaeda-allied Ansar Dine group, told AFP. "They are against us and against the French," he added. A local government official speaking on condition of anonymity said the attack occurred on the road leading to Menaka. "Everybody is afraid here in Kidal. The car bomb came from the centre of Kidal. That's scary, we don't know how many other car bombs are waiting in there," he said. Kidal is around 1,530 kilometres (950 miles) northeast of the Malian capital Bamako and the nearby Ifogha mountains have become a haven for Al Qaeda-linked fighters forced out of cities after France's intervention in January. Overwhelmed by the superior fire-power of the French air force and special forces, Islamist hardliners pulled out of the towns they had ruthlessly ruled for nine months, imposing an extreme form of sharia law. They regrouped and reverted to guerrilla tactics, launching hit-and-run attacks against French or pro-government forces and resorting to suicide attacks.