As per decades old tradition, the flag was taken inside the dargarh by members of Bhilwara's Gauri family, an official said.
The ceremony was conducted in the presence of a large number of devotees inside the holy shrine, he said, adding that the formal commencement will depend on the sighting of the moon on May 21-22.
Elaborate security arrangements have been made by the district administration in view of the large number of pilgrims expected to take part in the Urs, he said.