As part of the annual processions during the first ten days of Muharram, millions of Iranians in black outfits attend nationwide mourning rituals to pay tribute to Imam Hussein (AS) and his 72 companions.
On Tasua, eulogists and Islamic scholars narrate the events in the Battle of Karbala that occurred in 680 AD when the imam and his companions fought against the tyrant of thier time.
It is the day to honor Abbas, Imam Hussein's brother and general commander of his soldiers, who was sent to the Euphrates to bring water and was martyred on the way back.
Abbas made great sacrifices in the Battle of Karbala and was martyred shortly before Imam Hussein (AS) on Ashura, the 10th day of Muharram.
He is buried in the city of Karbala, which is located within walking distance from the shrine of Imam Hussein (AS).
The religious rituals of Tasua in Iran are in the form of mourning while people wear black and walk in long lines on the street.
The mourners repeat, alongside elegy reciters, some poems themed on events surrounding Imam Hussein's (AS) uprising and his battle against the corrupt ruler of his time
Ta'zieh, a Persian passion play, is another ritual held as a symbolic performance about the martyrdom of the Imam and his companions.
Among the famous rituals of Tasua and Ashura is distributing food as votive offerings to the mourners.
However, due to the coronavirus pandemic, this year's Muharram mourning rituals differ from previous years as all participants in the rituals must observe social-distancing and other health protocols strictly.