At least 37 people died early Thursday in Nigeria's oil-rich southern Niger Delta after inhaling fumes during the theft of fuel from a pipeline, a local NGO said.
Oil theft is a major problem in Nigeria, one of the continent's largest petroleum producers.
Accidents are common in swamps in the Niger Delta, where smugglers tap into pipelines to steal crude and refine it into fuel for sale.
"The Youths and Environmental Advocacy Centre (YEAC-Nigeria) has received and confirmed a report from its network of youth volunteers and human rights defenders in the Niger Delta in the Okrika Local Government Area of Rivers State that some persons, not fewer than 37 have been confirmed dead after inhaling 'Indorama fuel'," it said in a statement.
It said those killed are "suspected to be oil thieves", adding: "Many others are still missing."
It said "youths had connected a pipe to a tapping point on a pipeline that normally transports" crude from producer Indorama Eleme Petrochemical through the Port Harcourt Refinery to vessels loading for export.
The men tapped into the pipeline and were simultaneously loading into their own boats, it said.
"Many are still missing, and some corpses have been seen floating on the river but have not yet been recovered," the organisation said.
Police confirmed the incident but did not give a toll.
