The Sunnis also joined the Shias in mourning the martyrdom anniversary of Imam Hussein (AS).
Shia Muslims, and others in different parts of the world, hold ceremonies every year in the month of Muharram to mourn the martyrdom anniversary of Imam Hussein (AS) and his companions.
The third Shia Imam (AS) and a small group of his followers and family members were martyred by the tyrant of his time - Yazid Bin Moaweya, in the battle of Karbala on the tenth day of Muharram (known as Ashura) in the year 680 AD.