Nigerian farmers and the Dutch division of advocacy group Friends of Earth are suing Shell in a Dutch court for environmental damage caused by oil spills in the Ogoniland area of the Niger Delta. It's the first time a Dutch multinational company faces domestic civilian courts for overseas violations.
One of the plaintiffs told the BBC that Shell's environmental legacy in the region wiped out parts of the economy.
The U.N. Environment Report reported last year that oil pollution from more than 50 years of operations in the Ogoniland region is worse than previously suspected.
UNEP said that oil from a spill reported more than six years ago left a slick that was 3 inches thick at one groundwater site.
Shell, in a statement, said it was committed to cleaning up spills whether they resulted from sabotage or operational issues.
"The real tragedy of the Niger Delta is the widespread and continual criminal activity, including sabotage, theft and illegal refining, that causes the vast majority of oil spills," the company said.
The rebel Movement for the Emancipation of the Niger Delta has attacked oil facilities in the region. MEND says Delta residents aren't getting their fair share of state oil revenue.