Heavily armed militants raided a small village in Golaghat district, killing two Hindi-speaking persons as they were working in a field. One person was injured in the attack, they said.
Police reinforcements were rushed to the spot.
The ULFA has carried out a series of attacks on non-Assamese people, most of them Hindi-speaking persons from Bihar, since Friday in the districts of Tinsukia, Dibrugarh, Dhemaji and Sibsagar in upper Assam.
Earlier, a report from Dibrugarh said two persons injured in the attacks succumbed to their injuries at the Assam Medical College Hospital where they were being treated.
Hospital sources said 62-year-old Veer Bahadur Gajapati and 14-year-old Ajay Mahato, both brick kiln workers who were injured in an attack at Sepon Chagalia, died on Monday.