The U.S.-based Human Rights Watch says the main reason behind this year's violence in Nigeria's southern Niger Delta region is control of its oil wealth.
In a report released Wednesday, the human rights group said although the violence has both ethnic and political dimensions, it is essentially a fight over oil money -- both government revenue and the profits of stolen crude.
The group said the perpetrators of the violence are ethnic militias belonging to the three major ethnic groups in the region -- the Ijaw, Itsekiri and Urhobo -- as well as government security forces.
The report said during the first half of 2003, Ijaw militia members were particularly organized in attacking Itsekiri communities.
The rights group called on the Nigerian government to bring the perpetrators to justice.
Fighting between the Ijaw and the Itsekiri has claimed hundreds of lives in recent years and disrupted oil production which is vital to Nigeria's economy