In a victory for thousands of protesters opposing an oil pipeline in North Dakota, the US government on Sunday denied a permit for continued construction of the multibillion-dollar project, according to dpa. The Army Corps of Engineers denied the permit to the company behind the Dakota Access pipeline to drill under the Missouri River in the north-central US state. It was a major victory for the Standing Rock Sioux Tribe, whose protest against the pipeline had gone on for months and grew to several thousand people over the weekend. The native Americans said the segment of the 3.8-billion-dollar project would threaten burial sites and their water supply. The Army Corps of Engineers said it had based its decision on a need to "explore alternate routes" for the segment of pipeline. "Although we have had continuing discussion and exchanges of new information with the Standing Rock Sioux and Dakota Access, it's clear that there's more work to do," said Jo-Ellen Darcy, assistant secretary for civil works, in a statement. "The best way to complete that work responsibly and expeditiously is to explore alternate routes for the pipeline crossing." The Standing Rock Sioux said the corps would undertake an environmental impact statement and look for alternative routes. Interior Secretary Sally Jewell called it a "thoughtful approach" that would ensure "an in-depth evaluation of alternative routes for the pipeline and a closer look at potential impacts" took place.