A militant group in Nigeria says it has bombed three pipelines in the south of the country in the latest attack on the country's crucial oil industry.
The claim by the Niger Delta Avengers has not been independently confirmed.
The NDA, the latest militant group to emerge in Nigeria, is demanding that a greater share of oil wealth be spent on ending poverty in local communities.
Attacks resumed earlier this year after funding for former militants was slashed.
Nigeria is one of Africa's biggest oil exporters and it is the country's main export earner.
Nigeria's government and the Dutch-British oil company Shell, which operates the pipelines, have not yet commented on the alleged attack.
The NDA said it had blown up three trunk lines carrying 300,000 barrels of oil a day to Shell's Bonny export terminal in southern Bayelsa state.
Destruction of oil installations by successive militant organisations have severely disrupted crude production.
But an amnesty programme for former militants led to a period of relative peace until earlier this year.
Talks to resolve the conflict have been taking place in recent months, resulting in a delicate ceasefire, but those talks stalled at the beginning of November.
Since then there has been a sharp increase in attacks.
President stands his ground: By Martin Patience, BBC News, Lagos
The continued attacks on pipelines are slashing Nigeria's oil production - and hammering an economy reeling from its worst recession in years.
This month, Nigeria's President Muhammadu Buhari met leaders from the Niger Delta in a bid to end the violence.
The government also announced a vague plan to invest $1bn in the region - although it didn't spell out where the cash would come from.
Since the high-profile meeting, there have been a slew of attacks.
One of the militants told the BBC that the government was "playing with us" and that it wasn't putting its words into action.
Militant groups say they're fighting for a greater share of the resources for local communities. They also want the government to honour a previous amnesty programme - which offers cash payments and retraining - after its budget was slashed by two-thirds at the start of the year.
The government, however, accuses the militants of holding the country to ransom.
The continued violence is designed to pressure the government into making an agreement.
Despite the enormous economic pain, the president is standing his ground.