A Dutch court has ruled it has the authority to hear a case brought by a group of Nigerian farmers against oil giant Royal Dutch Shell. The four farmers claim a subsidiary of Shell is responsible for contaminating their land in the Niger Delta. They are seeking compensation and assurances that Shell will clean up the land polluted by alleged oil spills. Shell denies any responsibility and had argued that the court has no authority in the case. It said the spills, which sprung from a leak from a high-pressure pipeline in 2005 in Bayelsa State, were caused by sabotage by militant groups that have been fighting in the region.