Police fired in the air to disperse the mob, and the bullets hit an overhead high-tension electric wire that fell on the demonstrators.
Nine of them died on the spot and one died at Tinsukia Civil Hospital. Another person died on way to Assam Medical College Hospital in neighbouring Dibrugarh district.
Senior district civil and police officials, along with central paramilitary forces and police reinforcements, have rushed to the spot.
The officials were holding meetings with the protestors to pacify the situation, the police said.
Three days ago a man, his son and daughter-in-law were abducted by unidentified persons at Pangeree area. While the son escaped, the two others were killed, police said. Police arrested five persons in this connection and the mob had demanded that they be handed over to them for punishment.