Dozens of British musicians including producer Mark Ronson have signed an open letter to US President Barack Obama comparing the treatment of protesters at a controversial oil pipeline in North Dakota with "the same inhumane methods used during World War Two".
Led by singer-songwriter Kate Nash, around 160 names from the world of music wrote the letter to President Obama and the Department of Justice.
The disputed Dakota Access pipeline has seen hundreds of protesters set up camp to prevent building work taking place.
The pipeline is designed to carry oil from North Dakota to Illinois. Opponents, including the Standing Rock Sioux tribe, say it will harm drinking water and cultural sites.
Queen's Brian May, Alicia Keys and Green Day's Billie Joe Armstrong are among those who signed the letter which criticised the "extremely aggressive tactics" used against protesters by law enforcement, and called on President Obama to "take action".
Published by Nash on music site Noisey on Friday, the letter reads: " We are writing to express our shock at the treatment of the people of Standing Rock Sioux in North Dakota.
"We are deeply disturbed by the police actions that have been taking place, where non-violent protests have been and continue to be met with extremely aggressive tactics including; being shot with water cannons in below-freezing temperatures, chemical weapons, rubber bullets, and attack dogs.
"These are the same inhumane methods used during WWII and the Civil Rights Movement.
"We feel strongly in the current political climate that those in power must be held accountable for their actions."
Other signatories include Billy Bragg, Pink Floyd, The Strokes and Radiohead's Ed O'Brien.
The Obama administration said last month it wants more study and tribal input before deciding whether to allow an easement for the partially-built pipeline under the Missouri River reservoir.
The 1,200-mile pipeline would carry oil across four states to a shipping point in Illinois.