AMSTERDAM (AP) — Activists have scaled the front of Shell's headquarters and urged the company to "clean up" its operations in Nigeria, shortly before a Dutch parliamentary commission meets to discuss business in West Africa.

Shell remains the largest foreign oil operator in Nigeria's ecologically sensitive Delta region, despite attacks by local rebels seeking a share of profits. Shell says it now pollutes less and blames spills on thieves breaking into pipelines.

The Friends of the Earth activists arrived early Wednesday, some dressed as oil-smeared birds. Others hung plastic strips appearing to smear Shell's corporate logo and a banner reading: "Shell, let's go clean up Nigeria."