AlJazeera : Nigeria's main rebel group, the Movement for the Emancipation of the Niger Delta (Mend), is threatening to call off its ceasefire with the government if foreign oil companies do not leave their land.

Henry Okah, the group's leader, told Al Jazeera's Yvonne Ndege that the government has not stuck to its part of the deal and that "there will be a resumption of violence very soon".

Many of the armed groups argue that they are fighting for a greater share of oil revenue to remain in the Niger delt