Hundreds of activists gathered to block construction of the Dakota Access pipeline on Thursday. Police with tanks and riot gear surrounded them and began making mass arrests. One officer on the loudspeaker warned the demonstrators not to shoot "bows and arrows". For some Native American activists, the officer's comment was the latest sign that a highly militarized police force has little understanding of indigenous culture. The notion that the criminal justice system is biased against Native American protesters came into sharp view hours later, when a jury in Portland, Oregon, issued a verdict of not guilty for white militia leaders who staged an armed occupation of federal land to protest government policies. The fact that protesters with guns were acquitted on the same day police arrested 141 "water protectors", who have often relied on indigenous songs and prayers to convey their message, sparked a firestorm on social media. At the Standing Rock camps in North Dakota, where the fight against the $3.8bn oil pipeline is escalating ... Native Americans said the Oregon verdict was an infuriating and painful reminder that the law treats them differently - and that the odds are stacked against them in their ... battle to save their land. The ultra-conservative activists who seized the Malheur refuge were fighting against environmental restrictions aimed at protecting ... public lands. In North Dakota, the Native American-led movement is grounded in the idea that the land is sacred and must be preserved.