Arbaeen, one of the largest religious gatherings in the world, comes 40 days after Ashura, the martyrdom anniversary of the third Shiite Imam.
Each year, a huge crowd of Shiites flock to the Iraqi city of Karbala, where the holy shrine of Imam Hussein (AS) is located, to perform mourning rites.
In August, Iran and Iraq signed an agreement in Tehran to reopen the Khosravi border crossing and remove visa restrictions for Iranian Arbaeen pilgrims.
Iran and Iraq also agreed to raise the level of services and facilities for the pilgrims and enhance border security during the Arbaeen season, which will culminate in a large gathering in Karbala on October 19.
Source:Tasnim