Armed Zemi Naga tribals allegedly attacked Phaiding village at around 3:30 pm and killed the 55-year-old woman and injured two others.
The attack was in retaliation to the killings of two Zemi Naga villagers, who were shot dead yesterday allegedly by people of Dimasa community in the village, the sources said.
They had also set 21 houses on fire before escaping, they added.
Thousands of people have been rendered homeless by the turf war between ethnic communities in the district.
Two relief camps have been set up in Maibong and one each in Tunge, Jurai, Hajaichak and Mahur, the sources said.