Ashura, the 10th day of the lunar month of Muharram, marks the martyrdom anniversary of Imam Hussein (AS), the grandson of Prophet Muhammad (PBUH), and his 72 faithful companions in the Battle of Karbala in 680 AD.
Every year on Ashura, millions of Shiites around the world, dressed in black, take to the streets and mosques to mourn the sad occasion.
In Iran, devotees in cities, towns and villages across the country listened to elegies recounting the indescribably tragic events in the Battle of Karbala.
Here are photos of the mourning ceremonies held across the country: