An explosion at an oil production facility in southern Nigeria has killed seven workers, the country's state-run oil group said Wednesday.
The Nigerian National Petroleum Corporation (NNPC) said the blast happened during operations at the Gbetiokun OML 40 production platform in the Niger Delta region of the West African country.
"The incident, which occurred on Tuesday during the installation of a ladder on a platform ... unfortunately caused seven fatalities," the NNPC said in a statement.
The company said other workers on the facility have been accounted for, and an investigation has been launched into the incident.
The NNPC said the victims were employees of a firm engaged for the job.
Although Tuesday's incident was due to an operational factor, pipeline and tanker truck explosions are common in Nigeria, where most people live in poverty even though the country is the biggest oil producer on the continent, with around two million barrels per day.
Some incidents happen when residents try to siphon off oil or petrol from pipelines or when tanker drivers have accidents on the country's ill-maintained roads.
In March, a gas explosion in the commercial capital Lagos killed at least 15 people, injured many more and destroyed around 50 buildings.