[enter This paper firstly examines the unabated ongoing agitations for secession from the Federal Republic of Nigeria by the Yoruba and Igbo ethnic majorities who are indigenous to Southern Nigeria but also to some areas of Northern Nigeria. After years of unheeded calls for constitution amendment and restructuring that could heal the maladies of marginalisation, ethnic cleansing, and insecurity masterminded by religious terrorists and jihadists masquerading as herdsmen, the Yoruba and Igbo agitators have now insisted that they are no longer interested in either constitution amendment or restructuring but in having an Oduduwa Republic and a Republic of Biafra respectively. Even the predominantly Christian indigenous peoples of the southern parts of Northern Nigeria, who are popularly called the Middle Belt, have warned that they would never associate with the Muslim Core North if Nigeria breaks up. The reasons that the Southerners and the Middle Belters have alleged for their positions are marginalisation, ethnic cleansing and religious terrorism by some Core Northern ethnic and religious groups. The paper then examines in details the justifiability or otherwise of those secession agitations under international human rights law, some of whose instruments are domesticated by the Federal Government of Nigeria. Such rights as the right to self-determination, indigenous peoples’ rights, right to freedom of association, right to freedom of expression and right to life are considered vis-a-vis the ongoing conflict between some of the agitators and the Nigerian Armed Forces, which have had reasons to deploy airstrikes against suspected hideouts of militiamen agitating for a sovereign Republic of Biafra. The research adopts a doctrinal method and makes use of both primary and secondary sources of data from both the international and municipal forums. It finds out that a popular agitation for self-determination or secession referendum is an inalienable, natural and supranational right under both international law and the Nigerian municipal law and that those agitations must however be conducted peacefully. With South Sudan, Western Sahara, Eritrea, East Timor, Kosovo, Crimea and Brexit, among others, as precedents, it also finds out that it is the duty of the United Nations and other concerned members of the international community under the UN Charter and other relevant treaties to insist on the conduct of a referendum in the Nigerian case to avert an imminent full-blown civil war that could precipitate unprecedented humanitarian disaster in and beyond Nigeria, which is home to one-fifth of Africa’s population. The paper accordingly calls on the UN, African Union, Economic Community of West African States, United States, United Kingdom, European Union and other responsible members of the international community to act fast under the relevant international law instruments, more so as the whole world has now become a global village. Body]