Nairobi/Abuja - A Nigerian militant group Monday said it had destroyed a major crude pipeline belonging to Shell as it continued with a wave of attacks in the oil-rich Niger Delta.

Jomo Gbomo, a spokesman for the Movement for the Emancipation of the Niger Delta (MEND), said that engineers and fighters used explosives to destroy a Shell pipeline in Rivers State.

The report could not immediately be verified.

MEND on Sunday declared an "oil war" after Nigerian military forces attacked militant positions with gunboats and helicopters.

The group claimed to have killed 22 soldiers in an assault on a Chevron platform on Sunday and Monday said it had completely destroyed a Shell flow station, killing workers in the process.

Military spokesman Lieutenant Colonel Sagir Musa confirmed the attack on the flow station but said that no casualties were suffered.

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, helping to push up global oil prices and allowing Angola to surpass Nigeria as Africa's biggest oil exporter. (dpa)