This article originally published on June 5 has been updated.
As dozens of police officers march on in the streets of Buffalo, in the US state of New York, a 75-year-old man goes towards them and asks: "What are you doing?"
He is shouted at and police order him to move out of the way. One officer pushes him the man, who falls backwards, hitting his head on the pavement.
As the man lies on the floor, bleeding and seemingly unconscious, police officers walk on. Another stops to call for help.
The incident happened as people were protesting racism and marching in support of the Black Lives Matter movement on Buffalo's Niagara Square on Thursday, around 8 pm, the time the city's newly introduced curfew came into effect.
It comes after the death of George Floyd in Minneapolis sparked protests against police violence around the world.
Footage of the Buffalo incident quickly went viral on social media, sparking outrage.
Buffalo police initially said in a statement that a person "was injured when he tripped and fell," local media reported.
But an internal affairs investigation has been opened, a police captain later told the local TV station, and Buffalo's mayor, Byron Brown, announced that two police officers have been suspended without pay.
Brown said he was "deeply disturbed" by the video.
News update: Prosecutors say two Buffalo police officers have been charged with assault after a video showed them shoving a 75-year-old protester to the ground, AP reports on Saturday (June 6).
Both pleaded not guilty to second-degree assault.
The unidentified elderly man was transported to a hospital where he is "in serious but stable condition", Erie County Executive Mark Poloncarz said on Friday morning.
"Let’s hope he fully recovers," Poloncarz added.
Andrew Cuomo, the governor of New York State, has endorsed the officers' suspensions and described the events in the videos as "wholly unjustified and utterly disgraceful".
"The casual cruelty demonstrated by Buffalo police officers tonight is gut-wrenching and unacceptable," John Curr, the Buffalo chapter director for the New York Civil Liberties Union, said in a statement.
The incident should be a "wake-up call" for city leaders to address police violence, he added.
The Buffalo events are reminiscent of an incident in Nice, France last year, in which an elderly woman who was protesting peacefully was left bleeding on the ground after the police marched on the crowd. She said a police officer pushed her and footage of the scene appear to confirm her version. The woman, who remained several days in hospital with a fractured skull, later filed a complaint for violence.