RIYADH: Saudi clerics have accused Yemeni Houthi rebels of working with Iran to try to spread Shi'ism in Sunni Islam's heartland, days before the start of the Haj. "Iranian co-operation with Houthi rebels in Yemen is a collusion for sin and aggression," Grand Mufti Sheikh Abdul-Aziz al Sheikh said in remarks published yesterday. Riyadh launched an assault on Yemen's rebels 12 days ago after they staged a cross-border incursion that killed two Saudi border guards. A Yemeni army spokesman said armed forces and rebels fought a fierce battle in the rugged Malahidh area near the Saudi border.