Thousands of Nigerian fishermen have rejected an offer of $50 million from Royal Dutch Shell for "some of the largest oil spills in history," their British lawyers said Friday after winning a landmark court ruling, according to The Associated Press.

Shell has already accepted responsibility for paying compensation and cleaning up spills caused by its own failures, but the London High Court decided that Shell can be held legally liable for spills caused by oil thefts, if it fails to provide reasonable protection for its pipeline infrastructure, the AP reported.

Shell played down the judgment, saying in a statement that it was favorable in limiting litigation to "an assessment of actual damages sustained" in spills, according to the AP. The oil company, Nigeria's biggest petroleum producer, claimed that the court found Nigerian law "does not hold pipeline operators responsible for damage caused by oil theft."

Judge Robert Akenhead of the London Technological and Construction Court ruled Shell is responsible for taking reasonable steps to protect its infrastructure, including installing leak detection systems, surveillance equipment and anti-tamper equipment, the AP reported.

Shell does not have such equipment in its Nigerian fields, though they are considered mandatory in oilfields in the developed world, according to the AP.

Oil thefts in Nigeria have reached an industrial scale, with some $35 million worth stolen daily, according to figures this week from the country's national conference, the AP reported.

Shell has a woeful record of cleaning up spills in Nigeria and tt has yet to clean up the 2008 and 2009 spills that triggered the court case, saying the Bodo community has refused to give it access, according to the AP.

Mutiu Sunmonu, managing director of Shell Nigeria, said the company has accepted responsibility for the "deeply regrettable" spills and urged the fishermen to accept Shell's "sensible and fair compensation offers," the AP reported.

Martyn Day of London law firm Leigh Day said Shell's offer of 30 million pounds, or more than $50 million, which amounts to about 1,000 pounds for each of 30,000 people who lost their livelihoods is laughable, according to the AP.

Amnesty International has also accused Shell of manipulating oil spill investigations and wrongly reporting the cause and volume of oil spills devastating the Niger Delta, and of making false claims about cleanup measures, the AP reported.