US actress Shailene Woodley has been arrested during a protest in North Dakota against a huge oil pipeline project that will cross four states.
The Divergent star was arrested at a construction site as she was broadcasting the protest, which involved about 200 people, on Facebook.
Police say she was one of 27 people arrested on charges of criminal trespass and engaging in a riot.
The Dakota Access pipeline project has drawn huge protests.
Native Americans have halted its construction in North Dakota, saying it will desecrate sacred land and damage the environment.
In the Facebook Live footage, Ms Woodley, 24, said she had been walking peacefully back to her vehicle when “they grabbed me by my jacket and said that I wasn’t allowed to continue… and they have giant guns and batons and zip ties and they are not letting me go”.
As she was led away with her hands cuffed, she said she had been singled out from hundreds of other protesters “because I’m well known, because I have 40,000 people watching”.
The video spread quickly on social media and by early evening had been viewed more than 2.4 million times.
More BBC coverage of the North Dakota pipeline protests:
Ms Woodley, a star of The Divergent Series and the movie Snowden, has previously joined members of North Dakota’s Standing Rock Sioux Tribe to protest against the $3.7bn (£2.8bn) pipeline.
The protest on Monday took place at a construction site about two miles (3.2 km) south of the town of St Anthony.
The pipeline will run 1,168 miles through Iowa, Illinois, and North and South Dakota.
Energy Transport Partners, the company behind the project, has said it will boost local economies and is safer than transporting oil by rail or road.
But environmental protesters believe the transporting of up to 570,000 barrels of crude oil a day will imperil local waterways.
Native American tribes believe the pipeline would also damage historic sites.