In 1967, Emeka Odumegwu-Ojukwu, the military governor of Nigeria's then-Eastern Region inhabited mainly by Igbo people, accused the federal government of marginalising and killing thousands of ethnic Igbos living in the north.
On May 30 of that year, Odumegwu-Ojukwu declared the former Eastern Region a sovereign and independent republic under the name of Biafra - a unilateral move rejected by the federal authorities.
A bloody civil war ensued, with federal troops deployed to stop the secessionist movement.
The Nigerian forces cut off aid and access to the area throughout the war, which ended with the surrender of Biafra in January 1970.
The Republic of Biafra ceased to exist and General Yakubu Gowon, the leader of the federal government, famously declared that there was "no victor, no vanquished" in the war.
Fifty years on, the scars are yet to heal for many, including former fighters who suffered injuries and others who lost their loved ones and suffered huge economic losses.
On Monday, at a "Never Again" conference held in Nigeria's commercial capital of Lagos, Igbo leaders from the southeast urged the government to step up development efforts in the region and called for increased political inclusion and economic support to end fresh calls for a breakaway Biafra state.
In 2017, a regional court ordered the Nigerian government to pay 50 billion nairas ($138m, today's prices) in damages to civil war victims. The Economic Community of West African States Court of Justice also ruled that 38 billion nairas ($105m, today's prices) should be put towards evacuating abandoned lethal weapons which deprived southeast communities of farmland since the civil war ended.
But for Canada-based Igbo leader Benjamin Allison, financial reparation is not enough.
"You cannot compensate anyone for past injuries without an acknowledgement that a damage or harm had been done to them. Nonetheless, the only true compensation the Igbos seek from Nigeria at this point is a government based on fairness, equity and justice," Allison said.
Nigerian President Muhammadu Buhari in 2017 approved the payment of pensions of former police officers who served in Biafra during the civil war. The officers were granted a presidential pardon in 2000 by former President Olusegun Obasanjo.
The Nigerian government has repeatedly said it is committed to developing the region and recently undertook a series of road projects.
But Vincent Nnanna, who was barely 10 years old when the civil war broke out and was recruited to assist the Biafran soldiers with clerical work in Abia state, is not convinced by the government's efforts so far.
"The clamour for equity and respect for fundamental human rights by the Igbos in particular and the southeast at large has continued to fall on deaf ears," he said.
Separatist sentiment has not been wished away, and in recent years the pro-Biafra movement has seen some resurgence. The red, black and green flag of Biafra with a rising golden sun still dots the frontage of some commercial buildings and houses in the southeast region.
Rights group Amnesty International accused the country's security forces of killing at least 150 Biafra separatists at peaceful rallies between August 2015 and August 2016 and detaining hundreds demonstrating in support of a breakaway state. The military and police denied the allegations.
Nnamdi Kanu, a leader of the Indigenous People of Biafra (IPOB) group, is the most visible face of the movement. He was held for nearly two years for treasonable felony charges before being granted bail on health grounds in April 2017.
Kanu fled Nigeria under controversial circumstances in 2018 but still coordinates the group's activities from his base in the United Kingdom.
In 2017, following a number of IPOB-organised protests across Nigeria over a period of years, the government banned the group and declared it a "terrorist organisation".
"They masquerade as a separatist movement, yet they endanger the very people they claim to represent," Information Minister Lai Mohammed said in a 2017 statement about the government's move to outlaw the group.
"In reality, IPOB cares about IPOB and nothing more."
The government's pronouncement, however, has not stopped the group's activities - especially overseas where it enjoys the support of millions of Igbos in the diaspora.
"Continued agitation for Biafra is impelled and spurred by state-sponsored or supported injustice which left most Igbo youth with a sense of hopelessness and lack of outlets to express their ... talents, potentials and ambitions," Allison said.
He alleged that no real effort has been made to develop the region, support business, create jobs and ensure adequate security.
Nnanna, however, said he is not happy with the approach of those leading the calls for a new Biafra.
"The regrets I have over Biafra is that since after the death of the forebears, some mercenaries have emerged on the scene purporting to have the spiritual mandate to champion the Biafran cause to a positive conclusion - only for them to herd the ... crowd onto a blind alley, leaving the agitators confused and almost disillusioned," Nnanna said.
Meanwhile, Mohammed Sarki, a public affairs analyst, called for more efforts towards reconciliation.
"The continued discussions about the Biafra war won't help the country to move forward. Our leaders already declared that no side won the war. We need to forget the past and focus on how to fix Nigeria," Sarki said.
"The civil war was not a pleasant experience for many people, not just Igbos. We are better as a united country." SHARE THIS NEWS USING ANY OF THE BUTTON BELOW PLACE YOUR TEXT ADVERT BELOW ⬇⬇⬇