Nigeria is majority Muslim. The President of Nigeria is Umaru Yar’Adua, who also has the royal title of Mutawalli (custodian of the treasury) of the Katsina Emirate.
The people of the Niger delta believe they have not been treated unfairly by the government. The largest tribe, the Ljaw, are 95% Christian.
I suspect that someone that want to keep oil prices high is supporting them under the table.
The region is home to a huge industry of stealing oil and selling it on the black market.This trade is believed to fund the purchase of weapons.