Nairobi/Abuja  - Nigerian militants who have declared an "oil war" Monday said they attacked and destroyed an oil flow station complex owned by Shell in the restive Niger Delta province.

The Movement for the Emancipation of the Niger Delta (MEND) said Sunday it had begun operation "Hurricane Barbarossa" 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 the Shell flow station, killing workers in the process.

"Heavily armed fighters... stormed the facility and have razed it to the ground as promised," MEND spokesman Jomo Gbomo said.

"The foolhardy workers and soldiers who did not heed our warning perished inside the station," he continued.

The Nigerian military confirmed an attack on a flow station had taken place, but said that no casualties were suffered.

Nobody from Shell Nigeria was available to comment, but unconfirmed reports said that the company had evacuated dozens of oil workers.

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.

MEND said the latest operation would continue until the Nigerian government learned that "the solution to peace in the Niger Delta is justice, respect and dialogue."

The group also repeated previous warnings for oil companies to evacuate their staff and said that oil tankers should not attempt to dock.

President Umaru Yar'Adua on Wednesday announced the creation of a ministry to develop the region, which despite the oil money remains mired in poverty.

However, the previous body aimed at developing the region was hit by a corruption scandal and MEND has rejected the new ministry. (dpa)