Nigerian militants Sunday declared an "oil war" on the government, saying that hundreds of boats had been launched to attack oil installations in the restive Niger Delta province, reported dpa.
The Movement for the Emancipation of the Niger Delta (MEND) said in a statement that the mobilization of forces was in response to "unprovoked aerial and marine attacks" on MEND forces on Saturday.
"By dawn, destroyed oil flow stations, gun boats, burst pipelines, dead and injured soldiers trailed in the aftermath of the hurricane," MEND spokesman Jomo Gbomo said.
Gbomo said that 22 Nigerian soldiers had died in one attack on a Chevron Platform in Kula.
However, the Nigerian military said that it had repelled several MEND attacks, claiming it had inflicted heavy casualties.
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" and warned oil companies to evacuate their staff.
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.