Oil workers were on their way to extinguish a huge pipeline blaze in remote southern Nigeria on Wednesday, caused by a suspected dynamite attack that killed at least eight people.
Tuesday's attack by unknown gunmen on the pipeline operated by Royal Dutch Shell, in the Niger Delta's Opobo Channel, caused a major slick and fire, cutting output by 170,000 barrels per day (bpd).
"Supply of crude to that pipeline has stopped which means the fire will weaken. As we speak, people are on their way there to put it out," a spokesman for Shell in Nigeria said.
On Wednesday morning the fire was still burning strongly and thick black smoke billowed to the height of a 10-storey building, a Reuters witness said.
Shell, which has closed two oilfields to help curb the fire, said there was no estimate yet of how long the outage would last. It represents a 7 percent cut in output from the world's eighth biggest exporter of crude.
"We are still waiting to get more news on the Nigerian explosion. It appears to be a serious situation," Shell CEO Jeroen Van der Veer told Reuters on the sidelines of a gas deal signing ceremony in Qatar.
The Shell pipeline runs to the Bonny Light export terminal, but the company spokesman said he did not have any information yet about whether the outage was affecting exports or not.
Another pipeline, operated by state oil firm Nigerian National Petroleum Corporation (NNPC) and running to a refinery, was damaged in Tuesday's blast, an industry source said. No one at NNPC was immediately reachable for comment.
The nearby community of Asagba Okwan Asarama was deserted. About 20 huts, close to where Tuesday's blast ripped through the pipelines, were reduced to blackened ruins. A local fisherman, who was on the open sea when the blast took place, was desperately searching for his wife and four children. He said he did not know if they had fled or been killed in the explosion.
A local government official from Rivers state, where the community is located, said on Tuesday eight corpses had been recovered from the site and other people were missing.
The Niger Delta pumps almost all of Nigeria's 2.4 million bpd. Violence and sabotage targeting the oil industry are frequent in the vast region of mangrove swamps and creeks, where poor local communities feel cheated of the wealth extracted from their lands.
Industry sources have speculated that Tuesday's pipeline attack and two other recent security incidents at oil and gas installations in the delta could be part of a co-ordinated plan, though there is no certainty.
Motives could include revenge by supporters of the impeached governor of neighbouring Bayelsa state, who is due to face corruption charges on Wednesday, or frustration by oil thieves who have been hindered by a recent crackdown, sources say.