The main armed rebel group in oil-rich southern Nigeria said early Wednesday it was prolonging by 30 days its truce which expired at midnight. 'The Movement for the Emancipation of the Niger Delta (MEND) is extending its unilateral ceasefire which expired midnight (2300 GMT), September 15, 2009 by 30 days,' the group said in a statement. MEND, which has waged an 'oil war' targeting oil installations and the military deployed in the oil hub, declared in July a 60-day truce in response to a government offer for unconditional amnesty. The ceasefire came shortly after the release of its leader Henry Okah, who had been jailed for close to two years on charges of treason and gun-running. MEND says it is fighting oil companies operating in the Delta and the federal authorities to ensure that the desperately impoverished people of the Niger Delta benefit from the oil income. 