A Nigerian militant group maintained it was not negotiating a suspension to hostilities with the government, claiming responsibility for an attack on Chevron.

The Niger Delta Avengers surfaced early this year, launching a militant campaign against national and international energy companies working in the Niger Delta. The group accuses the government of Nigerian President Muhammadu Buhari of favoring oil and gas interests over the interests of the people in the Niger Delta.

In a statement, the group said it was countering the government's narrative that its campaign targeted Nigerian security forces and oil workers, instead blaming the administration of Buhari, a former military general, for some of the violence.

"It's their sleeper's agents that are doing it," spokesman Mudoch Agbinibo said in a statement.

Word surfaced last month of a 30-day truce between the government and the Niger Delta Avengers following talks apparently led by Nigerian Oil Minister Ibe Kachikwu. According to Vice President Yemi Osinbajo, the government was working to ensure "the man on the street in the Niger Delta" is getting a fair share of the revenue stream.

The Niger Delta Avengers said at the time it was not a party to any truce and the spokesman insisted again that the group has "not negotiated with anyone."

In a message corresponding with a major Muslim holiday, the militant group said its members bombed another installation used by Chevron.

"Happy Eid mubarak to our Muslim brothers," spokesman Mudoch Agbinibo said in a statement.

Nigeria is a member of the Organization of Petroleum Exporting Countries and pumped about 1.4 million barrels of oil per day in May, compared to almost 2 million bpd a year ago. By OPEC's estimates, militant activity has pushed Nigerian crude oil production to its lowest level in more than a decade.