A top Somali defense official said he survived an attack Monday by a suicide bomber driving an explosive-laden vehicle in the capital of Mogadishu. At least one bystander was killed. The attack against State Defense Minister Yusuf Mohamed Siyad comes as the besieged UN-backed government is preparing to launch an offensive against insurgents. Siyad said the bomber's vehicle chased his car, but exploded before colliding with it because a civilian minibus unexpectedly came between the two. Two bodyguards in a car driving behind the minister were wounded, Siyad said. As the convoy stopped to collect the wounded men, a second vehicle and then a wheelbarrow packed with explosives detonated nearby, Siyad said. Al-Shabab claimed responsibility in a statement released after the attack. They have previously used suicide bombs to kill government ministers, and are suspected of doing so last year in an attack on a medical school graduation in which four government ministers and 21 others were killed. Siyad used to be a member of the insurgency but joined the government in 2009. “This will not deter me from my national duties,” he said. “I used to patrol in the city (at) midnight and I will keep patrolling until we restore law and order.” A medical official said one bystander was killed and another seriously injured.