Buhari later made a televised address promising that the government would ensuring a free, fair and peaceful vote, without making any reference to the Avengers’ statement. His spokesmen did not immediately respond to requests for comment.
Attacks in the Niger Delta in 2016 cut Nigeria’s crude output from a peak of 2.2 million barrels per day (mbpd) to near 1 mbpd – the lowest level seen in Africa’s biggest economy in at least 30 years.
That, combined with low oil prices, pushed the OPEC member state into its first recession in a quarter of a century – crude sales make up two-thirds of government revenue and 90 percent of its foreign exchange.
 Atiku, a businessman and ex-vice president representing the main opposition People’s Democratic Party, has proposed to devolve more power to regions in a policy dubbed “restructuring”.
It would enable oil-rich states in the south to retain a greater share of the revenues generated from crude production.
“We are adopting Alhaji Atiku Abubakar, as the sole candidate to be voted for by all the people of the Niger Delta as a result of his political ideology which is in tandem with our agitation for equitable and fair principles of federalism,” the group said.
The Avengers said that, if elected, Atiku should start a “restructuring of Nigeria” within six months to forestall further attacks in the Niger Delta.
“Atiku has said that restructuring will begin on the day he takes office, so he will keep his word,” Paul Ibe, a spokesman for the main opposition candidate, said in a telephone interview.
Buhari’s government held talks with the militants in 2016 and 2017 about their grievances over poverty and oil pollution in the Delta.
No substantial attacks have been carried out by any groups in the Delta region since January 2017.
The country is also facing separatist movements in the southeast and Islamist militants in the northeast.  Reuters