The deceased has been identified as Jagjit Singh (45) and his children - Harmanbir Kaur (10), Jashandeep Kaur (8) and Jagsir Singh (8).
The farmer allegedly took the extreme step yesterday in Machaki Mal Singh village here as he had to pay back a loan of Rs 8 lakh, police said.
The wife of the deceased had left him three years back, they said.