DUBAI - A suicide car bomber killed six members of a Shi'ite Muslim rebel group and three civilians in northern Yemen on Friday, a local official said. Several others were wounded in the attack, which targeted the Shi'ite rebels, otherwise known as Houthis, who had gathered to pray at a school in the northern al-Jawf province bordering Saudi Arabia. Western and Gulf Arab states have watched with mounting alarm as al Qaeda-linked militants exploit political instability to gain a foothold in the impoverished state. Earlier on Friday, another suicide bomber targeted a Houthi protest march in the province of Saada, where they have effectively carved out their own territory. There were no casualties in the attack, the Houthi leadership said. On Monday, a suicide bomber dressed in army uniform blew himself up during a military parade rehearsal, killing more than 90 soldiers in an attack claimed by al Qaeda's Yemen-based wing. There was no claim of responsibility for either of Friday's attacks. Sunni Muslim militants inspired by al Qaeda view Shi'ite Muslims as heretics.