Nigeria's main militant group said that it would resume attacks on oil installations after a ceasefire expires next week.
The Movement for the Emancipation of the Niger Delta (MEND) said in a statement that it would burn down all oil installations it has attacked in the past and no longer limit attacks to pipelines.
MEND had declared a 60-day ceasefire on 15 July. In mid-September it extended its ceasefire by one month, holding off on attacks on oil installations and kidnapping foreigners, reported The Associated Press.
Attacks from MEND and unrest in the Delta region have cut Nigeria's oil production by about a million barrels a day.
Militant spokesman Jomo Gbomo warned oil companies operating in the country to disregard government claims that an amnesty programme was successful.
Several key Nigerian militant leaders have since agreed to participate in the amnesty programme.