Nigeria's leading anti-government militia has pledged to re-launch attacks on oil and gas projects 'soon.'

The Movement for the Emancipation of the Niger Delta (MEND) slammed an amnesty offer by President Umaru Yar'Adua, in a Wednesday statement, and promised renewed attacks on the oil installations after a three-month ceasefire, meant to restore peace in the southern oil-rich regions of Niger Delta.

The MEND guerrillas condemned the recent offer asking the fighters to lay down their arms and censured those who embraced the government disarmament proposal.

"Most of those who participated in this fraud were rented by the government in the hope that real militants would be persuaded to emerge," the militants said in their latest declaration.

The development comes in the aftermath of new government efforts to uproot militancy and help revive the teetering oil sector in Africa's largest producer of fossil fuels.

Instead, the group vowed fortified campaign against the government and said, "MEND considers this next phase of our struggle as the most critical," referring to the expiration of a government-brokered truce that will end next week.

"In this next phase, we will burn down all attacked installations and will no longer limit our attacks to the destruction of pipelines," MEND's statement read.

MEND launched an anti-government movement in late 2005 and has been vying for power via attacks on oil and gas plants.

Nigeria's central bank has estimated the damage inflicted on the oil and gas works by the group at about USD one billion per month.