Somalia's defence minister has survived an assassination attempt by a suicide bomber in the capital Mogadishu. Yusuf Mohamed Siyad told the BBC how a car was driven towards his vehicle and explosives on board were detonated, injuring two of his security guards. He said more explosions went off as he tried to collect the wounded guards. The BBC's Mohamed Olad Hassan in Mogadishu says the attack is the latest challenge to a government plan to tackle Islamist insurgents. Militant groups control much of the south of Somalia and are in constant conflict with the government. 'Committed to kill' But Mr Siyad said the latest attack would not distract him from his job. "I used to patrol in the city at midnight and I will keep patrolling until we restore law and order," he said. "This attack was a message from my enemy that they are committed to kill me and all the other government officials like me but for me it encourages me to be ready." He said an assassination attempt had been expected, and he had changed his plans to avoid being killed. In December, a suicide bomber attacked a graduation ceremony for medical students which was attended by senior officials. Three ministers died at the scene, and another minister died from his injuries last week. Rumours have been circulating for days that the transitional government is about to launch a major attack on hard-line insurgents. While hundreds of rebel fighters have poured into the capital in preparation for battle, thousands of civilians have fled the area. Somalia has been wracked by violence for much of the past 20 years. It has not had a functioning central government since 1991. Source: BBC