The arms and ammunition were recovered during an operation launched by Superintendent of Police Ranjan Bhuyan at Chapaguri on the National Highway, IGP L R Bishnoi told PTI.
The seizures include a US-made M-16 rifles along with its extension and silencer, a Mark IV 303 rifle along with two magazines and 141 rounds of bullets, Bishnoi said.
The arms were being transported through the vehicle from Merapani along the Assam-Nagaland border for National Democratic Front of Bodoland's self-styled Commander-in-Chief Bidai, the IGP said.