Ashura marks one of the holiest days in the Shi’ite calendar.
Hundreds of thousands of pilgrims gather each year in the Iraqi city of Kerbala to commemorate the killing of Imam Hussein, grandson of the prophet Mohammed in the 7th century, which became the formative event in Shi’ite Islam.
A minority perform the ritual of ‘tatbeer’. Wearing white robes they cut their heads with swords and spears in mourning over the Imam’s death.
It represents the beginning of tensions between Sunni and Shi’ite Muslims, which hangs on the question of succession following Mohammed’s death in 632. While Sunnis sought an elected caliph, the Shi’ites accepted only direct descendants of the prophet.
The day of Ashura marks the anniversary of the violent assassination of Hussein, the son of Ali, a descendant of Mohammed.
Tensions between Shi’ites and Sunnis continued through the ages, more recently in the aftermath of the Iran-Iraq war, thousands died in fighting carried out along sectarian lines.
Sunni extremists, who consider Shi’ites as heretics have been known to kill dozens of pilgrims commemorating Ashura every year.