Today is the 10th day of Muharrem in the Islamic Calendar and is the day when Shiites across the world mourn the death of Hussein Ibn Ali (the grandson of the Prophet Muhammad) in the Islamic year 61 at the Battle of Karbala (in modern day Iraq). Ya Libnan has some great photos of the mourning in Lebanon. The LA Times Blog has photos from Iran, where Ashura has been used to show dissent.
For Shi’a Muslims, Ashura is of great importance as it marks the break between Shi’a and Sunni sects within Islam and is marked by the Shi’a Muslims by displays of mourning that often include cutting oneself, beating their heads or being whipped with chains. This suffering is meant to connect themselves with Hussein.