The naxal attacks and the eagerness of lower castes to rise up in the socio-economic ladder and the opposition from the upper castes further culminated into the formation of caste-based "private armies" in Bihar. While most of these were formed by upper castes primarily the members of Rajput and Bhumihar caste. Some of the caste armies of new landlords from the backward castes like Kurmi and Yadav also existed. Ranvir Sena, Kuer Sena, Bhumi Sena are some of the notable caste armies.