A rebel group that has wreaked havoc in Nigeria's oil hub on Friday ended a 90-day ceasefire, warning the oil industry and military to brace for new and widened attacks. The Movement for the Emancipation of the Niger Delta (MEND), which has waged a three-year campaign for a bigger share of the oil wealth for the impoverished local population, said it will take up arms again after it shunned a government amnesty offer. MEND's violent attacks have severely cut daily production in the world's eighth largest oil exporter -- by up to a third of pre-2006 levels. The militant group said in a statement it was resuming 'its hostilities against the Nigerian oil industry, the Nigerian armed forces and its collaborators with effect from 00:00hrs, Friday, October 16, 2009.' But their former fellow fighters, who have accepted the government amnesty offer, have dismissed the threats as 'baseless'. 'As far as we are concerned, that is a baseless one because we don't know where it is coming from at this time when the key players have embraced the presidential amnesty,' a prominent ex-militant, Government Ekpemupolo, better known as Tompolo, said through his spokesman Paul Bebenimibo. 'People should ignore that declaration and begin to do out things that will bring enduring peace and development to the Niger Delta region,' the spokesman told selfnews. The government said last week that more than 8,000 militants have surrendered their arms in the amnesty including many of MEND's leading fighters. MEND ordered a truce in July to allow for possible talks with President Umaru Yar'Adua's government. It set up a committee -- which included 1986 Nobel literature laureate Wole Soyinka -- to run negotiations, but no formal talks are known to have taken place yet. The group rejected the government's amnesty offer, which it described as a 'charade', saying it failed to address the key issues of under-development and injustice in the Niger Delta. A prominent ethnic Ijaw leader and former information minister, Edwin Clark, urged the rebels to hold their fire. 'We are appealing to MEND not to resume hostilities. They should give peace a chance,' Clark told selfnews. Timiebi Koripamo-Agary, a spokeswoman for a panel overseeing the amnesty exercise, urged MEND to follow the action of their ex-fellow combatants who have embraced peace. 'I sincerely hope that MEND respects the wish of Nigerians... to end a chapter of violent struggle and participate in addressing fundamental issues for the healing growth of he Niger Delta and Nigeria,' she told selfnews. In the past three years Nigeria's oil output has been cut from 2.6 million barrels a day to 1.7 million currently. It has now been equalled by Angola as Africa's top exporter. And in the last year, Nigeria has also seen its foreign exchange reserves drop from more than 67 billion dollars to 40 billion. Hundreds of oil workers, including dozens of foreigners, have been kidnapped by MEND and other groups in the Delta region. It has attacked pipelines and offshore facilities and even Lagos harbour. Although there is no precise death toll, several hundred fighters and civilians have been killed in the region since 2006. Despite MEND's rejection of the amnesty, the government says there has been a good response. Yar'Adua told an OPEC delegation this week that the amnesty returned peace to the south of the country. The government has faced severe pressure over the conflict because 90 percent of the country's earnings come from oil. But MEND said in a statement last week that the next phase of its struggle would be the most critical as it planned 'to end 50 years of slavery of the people of the Niger Delta by the Nigerian government, a few individuals and the western oil companies once and for all.' It warned that future operations would be more destructive and not only be confined to destruction of pipelines. 