Thane: A mother-daughter duo has been booked by Thane police for extortion after they demanded Rs 50 lakh from a woman director of a private school and junior college in Ulhasnagar township here.

The accused identified as Sughanda Ramesh Patil (55) and Archana Patil (28) hail from Mharal village in Kalyan taluka here and demanded the sum as a ransom to free the director's son, who has been allegedly 'abducted' by them, police said today.