Over 275,000 people were reported missing at the Maha Kumbh Mela which began on 14 January, 2013 at Prayag, Allahabad.
The holy festival, identified as one of the world's biggest religious gatherings, has left many people separated from their families
About 15,000 people were reported missing on the auspicious occasion of Mauni Amavasye on Sunday.
"We have lost count after 12,000 who were reported missing since 4am this morning," Ashish Mishra, civil defense volunteer at one of the Lost and Found Centre in Prayag, told Gulf News, Sunday. "But we believe that around 15,000 people may have been reported missing."
"Most pilgrims are poor and illiterate who lose their sense of direction because of water on one side and millions of people on the other side," he added.
People from different parts of the country rushed to the lost and found centres to look for those lost at the holy festival.
The 'Lost and Found' online service, set up by the government in partnership with Datanet, helps pilgrims to track missing people. They have also announced several mobile numbers which people can use to report about missing and found persons.
The lost and found centers and online service have the list of missing as well as those found along with their photographs and details.
Millions of people across the nation gather at Kumbh Mela to take dip in the sacred river. It is held every third year at one of the four places by rotation: Haridwar, Allahabad, Nasik and Ujjain