They recite Adhan (call to prayers), perform Tawasheeh (religious songs) and recite verses from the Holy Quran in Moukebs (resting places with special facilities and services for pilgrims) on the path of the pilgrims.
Mohammad Hassan Movahedi, Mohammad Mirzakhani, and Hojat-ol-Islam Alipour are among the members of the convoy, which also includes a number of Tawasheeh groups from different parts of Iran.
By Sunday, some 20 million Shia Muslims from Iraq and other countries have marched toward the holy city of Karbala ahead of Arbaeen.
16 million Iraqis and over 3.5 million pilgrims from other parts of the world have attended rituals marking Arbaeen, the 40th day after Ashura, the anniversary of the martyrdom of Imam Hussein (AS) and his faithful companions in the 680AD Battle of Karbala.
Each year, a huge crowd of Shias march toward Karbala, where the holy shrine of Imam Hussein (AS) is located, to perform mourning rites.