Seven people have been killed in an explosion at the Gbetiokun oilfield in southern Nigeria's Niger Delta region during the installation of a ladder on a platform, the state oil company said on Wednesday.
"Detailed investigation of the cause of the explosion has commenced, while the Department of Petroleum Resources has been duly notified," the Nigerian National Petroleum Corporation said in a statement about the incident which happened on Tuesday.
It added that "all personnel on board the platform" had been accounted for.
Although Tuesday's incident was due to an operational factor, pipeline and tanker truck explosions are common in Nigeria, the biggest oil producer on the continent, with about two million barrels per day.
Pipelines in the region are exposed and often unguarded, making them easy targets for anyone with access to explosives.
International oil companies have increasingly focused on offshore projects in Nigeria, partly to offset the risk to onshore operations in the Niger Delta.
The latest accident occurred at OML 40, operated by a subsidiary of state-owned oil firm NPDC and the Elcrest joint venture. NPDC did not say whether production was affected.
Nigeria is battling the effect of lower crude oil prices on government revenues and its currency after the coronavirus pandemic crashed demand for supply.