Shell Nigeria shut its Trans Niger pipeline after a leak was detected, barely a week after the company re-opened the pipeline following the repair of some crude theft points.

“Details of this latest incident, including cause and size of spill, are unclear at the moment, but the TNP has been variously targeted by crude oil thieves in recent months and shut down several times to enable the removal of theft points,” Shell Nigeria spokesman Tony Okonedo said in a statement.

“A total of about 150,000 barrels per day of oil have been deferred.”

Shell said that it had re-opened the Trans Niger Pipeline (TNP), running through Nigeria’s oil-producing Niger Delta region, after repairing a valve point and removing oil theft connections.

But Okonedo said by telephone that a new leak on a different section of the pipeline meant it had to be shut down again, adding that some oil had been spilt. His statement said the Shell Petroleum Development Corporation, a Shell-run joint venture majority owned by Nigeria’s government, was “mobilizing to respond as quickly as possible to the spill.”

The last time the TNP was shut, a local environmental NGO estimated 6,000 barrels of oil had been spilt. The area that the TNP crosses, Ogoniland, has been devastated by repeated oil spills. Environmental groups argue that Shell’s 50-year-old infrastructure in the area is decrepit and must be shut down or replaced.