FACTBOX: Nigerian militant campaign hits oil production

(Reuters) - Militants in Nigeria's oil-producing Niger Delta said they had attacked a major oil crude pipeline late on Friday, the latest in a week of strikes against Africa's biggest oil and gas industry.

Following are details on the facilities the main militant Movement for the Emancipation of the Niger Delta (MEND) claim to have attacked over the past week and what the operators have said.

PRODUCTION IMPACT

Royal Dutch Shell, which operates facilities in the Niger Delta through its SPDC joint venture with state oil firm NNPC, declared force majeure late on Friday on Bonny Light oil shipments because of the unrest.

The move, which frees it from contractual obligations, comes in addition to an earlier force majeure declared as a result of attacks on a key pipeline in July.

With so many attacks on varied locations, coming on top of repair work already being carried out on facilities across the delta, it is difficult to give precise figures for the production impact.

Shell has given no figures.

Nigerian government officials say oil output from Nigeria, the world's eighth biggest exporter, has fallen by 150,000 barrels per day over the past week and estimate the country's production at 1.95 million barrels per day.

OIL PIPELINE AT BUGUMA FRONT

MEND said they had attacked a major pipeline operated by Shell at Buguma Front in Asari Toru local government area of Rivers state late on Friday, September 19.

Shell said on Saturday it was investigating reports of an attack on a pipeline belonging to its SPDC joint venture, but gave no further details.

OIL PIPELINE AT CAWTHORNE CHANNEL

MEND said its fighters had blown up a major pipeline operated by Shell at the Elem-Kalabari Cawthorne Channel axis in Rivers state late on Thursday, September 18.

Shell said it was continuing to check its SPDC joint venture facilities for possible damage but gave no further details.

OIL PIPELINE AT RUMUEKPE

MEND said it had blown up a crude oil trunk pipeline which it believed belonged to both Agip and Shell on Wednesday, September 17.