The deceased have been identified as Aneeta Bagya Barela (2), Mukesh Bagya Barela (7) and Fundabai Raju Barela (7), Investigating Officer Suryakant Laxman Patil said.
The incident occurred yesterday when the trio, who were children of labourers, were sleeping near a field, he said.
The tractor-borne accused identified as Sunil Bhimsingh Barela, who was cutting grain in the field, mowed them down, killing them on the spot, he said.
The accused fled the spot after the mishap, but was later nabbed, he said.