Nairobi/Abuja  - The main militant group in Nigeria's oil- producing Niger Delta region Friday called off a long-term ceasefire, citing an attack on one of its camps.

The Movement for the Emancipation of the Niger Delta (MEND), which in September declared a ceasefire after a week of attacks platforms, pipelines and oil flow-stations owned by Chevron, Shell and Agip, said it would resume hostilities.

"The oil industry should ... brace itself for Hurricane Obama; a sweeping assault starting from Rivers state that will change the face of oil and gas exports from Nigeria," MEND spokesman Jomo Gbomo said in a statement.

Militant groups such as MEND often attack oil installations and kidnap expatriate workers, saying they are fighting for a greater share of profits from oil exploitation for the poor of the region.

The government says they are merely criminal gangs intent on stealing oil and extorting money.

The unrest has cut oil production by around a fifth since early 2006. (dpa)