Shell said it has again shut down a key supply pipeline in southern Nigeria owing to leaks, reducing output by 150,000 barrels per day of crude, barely two weeks after repairing the affected line.

The Nigerian subsidiary of the Anglo-Dutch oil giant, SPDC said late on Wednesday that the Trans Niger Pipeline (TNP) was shut down "following reports of new leaks, barely 10 days after the line was repaired from crude oil theft incidents."

It said daily production of some 150,000 barrels of oil is affected.

Shell said the latest leaks occurred at the oil-rich but restive southern Ogoniland, adding that the TNP was shut "as a precautionary measure after receiving reports of the incidents."

The company said it would send an investigation team to determine the cause and impact of the spills.

The pipeline was shut down last month for repairs after two separate crude oil theft incidents.

Local Channel television on Thursday broadcast a footage of some Ogoni villagers scooping oil from the spill site, sparking fears of petrol fire.

More than 100 people were burned to death in July last year near the oil city of Port Harcourt when the tanker from which they were scooping petrol caught fire.

The tanker had swerved trying to avoid three oncoming vehicles.

Oil theft is a major problem in Nigeria, and Shell has consistently blamed its losses on thieves vandalising its pipelines.

However, environmental activists argue that Shell does not do enough to prevent such incidents and effectively clean up the damage when they do occur.

Nigeria's oil-producing region is badly polluted from decades of oil spills, and Shell is the biggest producer in the west African country, where it has been operating for over 50 years.

Nigeria produces some two million barrels a day of oil and is Africa's largest exporter.