The Movement for the Emancipation of the Niger Delta (MEND) has rejected the sentence on its leader, Henry Okah.
He was sentenced to 24 years in prison by Justice Neels Claaseen of the South Guateng High Court in South Africa.
He was found guilty of several charges of terrorism in the Independence Day bombings in Abuja in 2010.
In a statement signed by one “Comrade Azizi,” on behalf of MEND, the group said, “Boko Haram has killed more innocent Nigerians than any other militancy groups in the country and yet their spokesperson was handed a three year sentence, this is the height of injustice to our region and people which will be resisted by all means necessary.”
The statement said that consultations were ongoing with some stakeholders and elders of the region and that its position will be made known thereafter.
“The gate of hell has just been let lose, (sic),” the statement declared.