A group of US environmental activists engaged in non-violent civil disobedience targeting the oil industry have been listed in internal Department of Homeland Security documents as “extremists” and some of its members listed alongside white nationalists and mass killers, documents obtained by the Guardian reveal.

The group have been dubbed the Valve Turners, after closing the valves on pipelines in four states carrying crude oil from Canada’s tar sands on 11 October 2016 which accounted for about 15% of US daily consumption. It was described as the largest coordinated action of its kind and for a few hours the oil stopped flowing.

The five climate activists, members of Climate Direct Action, cut their way through fencing and turned the valves. The activists notified the energy companies whose pipelines were being disrupted and posted videos of their protest online and waited patiently to be arrested.