Ahmed Jalil al-Shimri, director of the medical bases of the Astan (custodianship) of Imam Hussein (AS) hoy shrine, said they have travelled to Iraq from Iran, Australia, Tanzania, India, Pakistan, Bahrain, Saudi Arabia, Kuwait, Lebanon and Syria.
He added that the Astan has established 35 medical bases in Karbala and three medical centers on the roads leading to the holy city.
They all provide 24-hour services to the pilgrims, al-Shimri went on to say.
Arbaeen comes 40 days after Ashura, the martyrdom anniversary of the third Shia Imam, Imam Hussein (AS).
Each year, a huge crowd of Shias flock to Karbala, where the holy shrine of Imam Hussein (AS) is located, to perform mourning rites.
Arbaeen will fall on Saturday, October 19 this year.