A Nigerian militant group admitted to an attack on a crude oil export pipeline, but blamed a rogue member for violating a truce, a Nigerian newspaper reported.

A spokesman for the Movement for the Emancipation of the Niger Delta, Jomo Gbomo, was quoted by Nigerian newspaper Vanguard as saying it took full responsibility for an attack on an export pipeline the Niger Delta region.

"The attack was however, unauthorized by our high command given the fact that the MEND unilateral ceasefire of hostility against Nigeria's oil and gas assets declared May 30, 2014 is still in force," he said.

MEND has pushed for more influence for Niger Delta communities in the regional oil sector. It ramped up its militancy in the Niger Delta after leader Henry Okah was sentenced in South Africa to 24 years in prison on terrorism-related charges in 2013, but brokered a truce the following year.

"Within the preceding six months of this year, MEND has worked assiduously to bring peace to the troubled Niger Delta region and hereby assures Nigerians and the international community of our unflinching support for President [Muhammadu] Buhari's efforts to bring permanent peace to the region," the spokesman said.

The government blamed instability in the Niger Delta for its failure to meet a 2013 production target of 2.53 million barrels of oil per day. Total crude oil production in September, the last full month for which data are available, was around 1.52 million bpd, about 20 percent less than it was last year. A budget, meanwhile, from the government in Abuja is based on production of around 2.2 million bpd.

Recent instability in the Nigerian oil sector has been attributed to a group calling itself the Niger Delta Avengers, which in late October took credit for an attack on an oil export pipeline in Nigeria operated by Chevron.

The militant group, which surfaced early this year, is fighting for a greater share of the oil wealth from Nigeria, which is a member of the Organization of Exporting Countries. The group has been in various stages of peace talks with the government since the summer.

The Nigerian National Petroleum Corp. said it lost out on hundreds of thousands of barrels of crude oil due to unrest and banditry during the first several months of the year.