The forces have been sent in addition to 9,000 paramilitary personnel already deployed in the northeastern state to maintain law and order there, official sources said.
Shoot-at-sight order was issued today and indefinite curfew clamped in entire Kokrajhar, where the toll in the ethnic violence mounted to 19.
Concerned over the violence, Home Minister P Chidambaram called up Chief Minister Tarun Gogoi, who briefed him about the latest developments and the steps taken by the state government to bring back normalcy in the troubled areas.
Home Ministry officials, including Union Home Secretary R K Singh, are in regular touch with the state government officials and offered all possible help to defuse the situation.
Sources said Assam government officials informed the Home Ministry that the violence has spread to 400 villages located in 8,000 sq km areas.