TEHRAN- Ayatollah Seyed Ali Khamenei, Leader of the Islamic Revolution, attended the opening ceremony of the mourning rituals conducted at the Imam Khomeini Husseiniyah late on Monday to commemorate the martyrdom anniversary Imam Hussein (AS).The Battle of Karbala in 680 AD resulted in the martyrdom of Imam Hussein (AS), the third Shia Imam and a grandson of Islams Prophet Mohammad (PBUH), as well as his 72 companions.Every year, during the lunar month of Muharram, Shia Muslims commemorate martyrdom of Imam Hussein (AS) and his companions.