Saudi artist: Standing Rock protesters are warning us to save what we can – video

After the US Army Corps of Engineers denied a permit for the Dakota Access pipeline to drill under the Missouri river, Saudi Arabian artist Ahmed Mater joins protesters at Standing Rock to celebrate their victory. This is the fifth episode in our Crossing the line series, in which a group of Middle Eastern artists embarks on a US road trip exploring common concerns

• Standing Rock protesters asked to ‘go home’ by Sioux leader