Nigerian President Muhammadu Buhari delivering a televised speech last month in which he stressed the importance of unity. (File Picture: Reuters)

Nigeria's Senate has declared that the country’s unity is not negotiable following a two-hour closed-door session on Tuesday which addressed calls by the House of Representatives to investigate calls to restrict some sections of the country, Vanguard newspaper reported.

The House said it would establish a committee to study issues raised by agitators towards addressing the demand for restructuring the country, and revisit aspects of the constitution dealing with power devolution.

President Muhammadu Buhari has prioritised the issue of national unity. The office of the presidency welcomed the House’s resolution “in the face of daunting challenges and threats by certain groups, who are bent on causing disharmony and disunity among Nigerians”.

But Institute of Security Studies researcher, Ndubuisi Christian Ani, has accused Nigeria’s military of adopting a heavy-handed response to a growing separatist swell in the south-east among organisations claiming to be the successors of the failed late-1960s Biafra secessionist movement.

His comments came as Nigeria this month embarked on “Operation Python Dance”, a show of force to quell the Biafra agitation.

The exercise targeted supporters of the Indigenous People of Biafra (Ipob) and leader Nnamdi Kanu, who has been central to the Biafra agitation since 2015.

Several pro-Biafrans have been arrested and the military has been accused of brutality, arbitrary killings and torture.

Over 150 Ipob supporters were killed on last year’s Biafran Remembrance Day, human rights group Amnesty International reported.

“While the Nigerian military has labelled Ipob a terrorist organisation, opinions in the country differ on the response to the pro-Biafra movement,” said Ani.

“Some say the separatist activism must end, but many analysts agree that the government’s military response - as it was with Boko Haram - could further popularise the movement. It could also lessen the opportunities for dialogue and foster militancy in the region.”

The latest moves for independence have brought back memories from 50 years ago, when Dim Chukwuemeka Odumegwu Ojukwu, a former colonel of the Nigerian Army, sought to establish the State of Biafra.

Ojukwu’s declaration of secession in 1967 led to a bloody civil war that lasted until 1970.

Depite the restoration of Nigerian control of the Biafra region was in 1970, the agitation lingered.

However, some observers say the recent call for Biafran independence is an attempt to undermine the administration of Buhari, a northerner.

According to Professor Ufo Okeke-Uzodike, executive director of the African Heritage Institution in Nigeria, separatist activism has been fuelled by perceptions of discrimination and marginalisation.

Calls for an Oduduwa Republic in the south-west have come from the Yoruba Liberation Command in addition to calls for a Niger Delta Republic in the south.

“Even in the north, there is a growing quest to liberate the Hausa from perceived Fulani hegemony. The Boko Haram insurgency that has exhibited extreme violence in its fight for an independent Islamic state counts among Nigeria’s secession challenges,” said Ani.

But the secessionist call is strongest in Biafra and the grievances that led to the Biafra declaration of independence and the civil war remain.

Ipob regularly cites perceptions that Igbos are marginalised by the federal government in terms of infrastructure and appointments in state institutions.

Yet repeated strong responses by the authorities have only further stoked the conflict.

The Boko Haram insurgency has been blamed partly on the government’s killing of former leader Mohammed Yusuf in 2009 - a time when the group mainly exhibited radical views without violence.

“The recent killings of members of the Islamic Movement in Nigeria, a Shia group in the north, also raise fears of potential unrest in the region,” said Ani.