The Nasarawa State of Nigeria was ravaged between 2014 and 2017 by the militant activities of the Ombatse ethnic militia in the course of promoting the socio-political interests of the Eggon ethnic group. Efforts of concerned stakeholders at resolving the crisis have remained futile. The aim of this study was to investigate the effects of the Ombatse militia crisis on community security in Nasarawa State. The Objectives of the study were to (i) identify the socio-political interests of the Ombatse militia in Nasarawa State; (ii) examine the strategic approach of the Ombatse militia at achieving their socio-political interests; (iii) investigate the factors responsible for the transformation of peaceful demands of the Ombatse militia into a violent agitation (iv) examine the effects of violence activities of the Ombatse militia on community security; and (v) identify the challenges of resolving the Ombatse crisis.rnMixed research design, which combined quantitative and qualitative data collection techniques, was adopted for the study. Questionnaire was used for collecting quantitative data and Key Informant Interview along Focus Group Discussion was adopted for gathering qualitative data. 500 respondents were used as sampled population while data analysis for the study was based on the 485 retrieved data from both the quantitative and qualitative techniques. The data collected were interpreted withrn10rnthe use of percentages and descriptive analysis. The validity of the instrument and reliability of the results were obtained through the use pilot study and test-retest technique respectively.rnThe findings of the study were that the:rn(i) socio-political interests of the Ombatse ethnic militia in Nasarawa State included the creation of more Eggon chiefdoms (97%), more Eggon local governments (94%), acceptance of Eggon as indigenes of their places of abode within the state (92%), and repudiation of payment of farm royalties by the Eggon to the Alago chiefs (87%);rn(ii) main strategic approaches of the Ombatse militia at achieving the Eggon socio-political interests were persuasion (92%), aggressive use of Eggon media for mobilizing folks for violence (89%), adoption of physical violence against perceived enemies (87%); and charm fortification of members against defeat (53%).rn(iii) factors responsible for the transformation of peaceful agitation of the Ombatse militia into violent included non-creation of more Eggon chiefdoms (93%), non-election of Eggon as governor of Nasarawa State (86%), and non-repudiation of payment of farm royalties by Eggons to Alago chiefs (82%);rn(iv) effects of the Ombatse militancy on community security in Nasarawa State were loss of lives and property (97%), security breaches (81%) and strained relationship between the Eggons and other ethnic groups (73%), and;rn(v) challenges of resolving the Ombatse crisis included non-implementation of previous recommendations on the crisis (78%) and non-compromised position of the Ombatse militia on some unrealistic demands (71%).rnThe study concluded that the Ombatse militancy has breached community security and heightened inter-ethnic hatred in Nasarawa state without adequate resolution. Nasarawa State Government and the Eggon ethnic group should adopt better strategies for resolving the crisis.