The woman disappeared along with the children -- Raj (5), Sana (2) and Saba (3) -- late Saturday night, and was yet to be traced.
According to police, Chotu of Mohalla Shekhan in Agra's Achnera town, his five-year-old son, sister, brother-in-law and their two minor daughters were on a pilgrimage to the Kaliyar Dargah in Roorkee.
"The woman befriended them while they were waiting for a train at Mathura railway junction...," a police officer said, adding that "the woman fled with the children when they fell asleep at the junction".
A hunt is on to trace the woman and the children, the officer added.
