Illegal oil refineries in the Niger Delta – in pictures

A labourer drags a hose used to help siphon crude oil in a makeshift refinery on the banks of the Nun river. The practice is known locally as oil bunkering Photograph: Akintunde Akinleye/Reuters

A worker collects crude by hand from a hole in the ground which acts as a storage tank for crude oil. The oil is taken from one of the thousands of pipelines which run through the Niger Delta Photograph: Akintunde Akinleye/Reuters

A labourer feeds a fire with crude oil at the illegal refinery Photograph: Akintunde Akinleye/Reuters

Vessels used by labourers lie on the ground after a meal Photograph: Akintunde Akinleye/Reuters

A worker carries makeshift buckets of oil. The refined product is sold on locally Photograph: Akintunde Akinleye/Reuters

Refinery workers are reflected in a pool of polluted water Photograph: Akintunde Akinleye/Reuters

A warning sign belonging to Royal Dutch Shell on the banks of Nembe creek in Bayelsa state. The company has approximately 6,000 kilometres of pipelines running through the country. Photograph: Akintunde Akinleye/Reuters

Steam rises from pipes carrying refined oil from a burner into containers Photograph: Akintunde Akinleye/Reuters

A young woman sits in a canoe while fishing in a tributary of the river Nun. She suffers skin irritation from exposure to crude oil in the polluted water Photograph: Akintunde Akinleye/Reuters

A petrol station which has no fuel for sale near the oil city of Port Harcourt. Nigeria's finance ministry has reported that one-fifth of the country's 2m barrels-per-day oil output was stolen last year Photograph: Akintunde Akinleye/Reuters