Two US police officers were sued for pushing an elderly demonstrator, knocking him to the ground and causing a head wound during a march in the American city of Buffalo.
And US media reported Saturday that the lawsuit included a charge of serious assault.
They pleaded before the New York State City Court that they were not guilty.
A video showed that the policemen forcefully pushed the old man during a march that organized the beginning of the curfew, which led to his fall to the ground and a bleeding to the head.
The policemen were suspended after the attack, and the mayor of Buffalo Byron Brown and New York Governor Andrew Como condemned the attack, and the latter called for the police to be expelled and continue to bring criminal charges against them.
Many police officers in Buffalo have expressed their support for their colleagues.
The video shows a line of police officers walking on a street, then two of them push the seventieth man.
The injured man, Martin Gonio, is in a "serious but stable condition", according to his lawyer, who explained that he was a peaceful protester who had long been active in the defense of human rights.
During the past few days, demonstrations were organized in many American cities against racism, police violence and social injustice after the killing of an American policeman, George Floyd, strangled by an American policeman in Minneapolis, Minnesota on May 25.
Some protests developed into clashes and sabotage.