Western oil companies evacuated staff from three oilfields in Nigeria's southern Niger Delta on Tuesday after gunmen killed 12 people including four community chiefs in a dispute over oil money.
A spokesman for Royal Dutch Shell said there was no impact on production, while a spokesman for Chevron declined to comment. The two companies operate oilfields in the area accounting for about 60,000 barrels per day of production.
Sources in the Kula community where the attack took place said it was caused by a long-running dispute between local factions over the distribution of money given by oil companies operating there.
The attack took place on Sunday, when gunmen opened fire on a small ferry carrying 14 passengers to Kula in the coastal area of Rivers state, a maze of mangrove-lined creeks. "There are just two survivors who are being treated for bullet wounds in Port Harcourt," said a police spokeswoman in the Rivers state capital.