The arrested have been identified as Arjun (23) and his mother Fulo Devi.
"The mother-son duo was arrested yesterday for killing nine-year-old Rohit by pushing him into a dry well on Wednesday," Kartarpur DSP Jasvir Singh Rai said.
According to police, Arjun, a factory worker, took the boy to his house and asked him to call his 15-year-old sister and tell her to marry him. When Rohit refused to do so, Arjun with his mother's help threw him into a 50-feet-deep dry well.