A prominent Black Lives Matter activist has live-streamed his own arrest at a protest in Baton Rouge, Louisiana, as tensions rise between US police and racial minority groups.
The demonstration on Saturday night (US time) was one of several in US cities following the death of two black men shot dead by white police officers, their dying moments captured in shocking video footage that went viral online.
The situation is also tense in Dallas, where five officers were killed by a black man during a protest rally. Security levels were raised at the police HQ after anonymous threats were received but an all clear was given after a search of a car park for a "suspicious person".
One of the men killed by a white police officer was Alton Sterling, killed in Baton Rouge, in the southern state of Louisiana, where protests are intensifying.
Black Lives Matter activist DeRay Mckesson travelled to Baton Rouge for Saturday's protest, and was walking on the side of a road live-streaming the demonstration on Periscope."No justice, no peace, no racist police!" activists chant, as police cruisers follow the group.
Then suddenly the video is interrupted. "City Police. You're under arrest - don't fight me," a voice says.
Another protester grabs the phone and continues the video, asking police why Mr McKesson was detained. Pictures on social media show Mr Mckesson with his hands behind his back being taken away by police.
Dozens of people were reported to have been arrested and at least two firearms confiscated.
Arrests in Baton Rouge, other cities
A Louisiana state police officer told a reporter with The Advocate, a Baton Rouge publication, that Mr Mckesson was arrested because he had been blocking the road - though in his video Mr Mckesson said there was no sidewalk on the road.
"We welcome the protests," the officer told The Advocate in a video posted online. "We wouldn't arrest people who are quietly protesting off the roadway."
Two activists who were witnesses told The Washington Post that it was a physically violent arrest. "He was clearly targeted," said activist Brittany Packnett said.
Local media said some 30 people where arrested in the Baton Rouge protests.
Hundreds of people marched late on Saturday in several US cities protesting police abuses.
In St. Paul, Minnesota, several hundred protesters blocked a highway intersection for about three hours and hurled rocks and bottles at police, who were equipped with helmets, clubs and gas masks.
The officers used smoke grenades, pepper spray and tear gas to break up the crowd, and about midnight arrested protesters who refused to move.
Several hundred protesters blocked roads and bridges in San Francisco and Fresno in California, hundreds more protested peacefully in West Palm Beach, Fort Lauderdale and Miami in Florida.
In New York, at least 20 people were arrested as hundreds of protesters marched through Manhattan.
- ABC / BBC / Wires