The three accused - Latumian Laskar, Shebul Ahmed and Putul Ahmed - were nabbed from Borkhola town in Cachar district late last night.
The accused in the case, Dibyendu Shekhar Kar, who is also a lawyer, was arrested on August 15 from Borkhola. Kar is currently in police custody.
Several prominent organisations and NGOs had staged protests in the last few days to demand arrest of the four accused.
The girl, a student of Silchar Womens College and hailing from Guwahati, was forcibly picked by four persons and taken to Kumbhirgram airport road in Silchar and raped on August 11, the police said.
The accused had threatened of dire consequences if she reports to the police. She filed an FIR with Silchar police station on August 14 after the arrival of her mother and sister from Guwahati.
Cachar District Bar Association has already expelled Kar from its membership.