A view of an illegal oil refinery is seen in Ogoniland outside Port Harcourt in Nigeria's Delta region March 24, 2011.Crude oil thieves -- known locally as "bunkerers" -- have been a fact of life for years in Africa's biggest oil and gas industry, puncturing pipelines and costing Nigeria and foreign oil firms millions of dollars in lost revenues each year.

Smoke rises from an illegal oil refinery in Ogoniland outside Port Harcourt in Nigeria's Delta region.

Oil surfaces on water near an illegal oil refinery in Ogoniland outside Port Harcourt in Nigeria's Delta region March 24, 2011.