Millions of devotees converge on the holy city to commemorate one of the most important holidays of the Shiite religious calendar.
The attack took place killing one, but an important safety device is in place to prevent any attack against the crowd as explained in the governor of the province of Karbala.
"We believe that the success of this pilgrimage is one of the finest chapters victory of our armed forces and volunteer fighters against the organization Islamic state."
Songs and a reverence for Arbaïn which marks the end of the 40 days of mourning following the anniversary of the death of Imam Hussein, grand-son of the Prophet Muhammad.
Pilgrims throng around the mausoleum of Imam Hussein.
This year the pilgrimage took a more political dimension swathes of Iraqi territory having fallen into the hands of Sunni jihadist Islamic State group who consider Shiites as heretics.
