Almost two years after the killing of African American George Floyd in a police operation in the United States, three ex-police officers involved have been convicted.

A jury found the men guilty of violating Floyd's constitutional civil rights in federal court in Saint Paul, Minnesota, the US Department of Justice said on Thursday.

The ex-police officers were accused of not providing medical assistance.

Two of the men were also found guilty of failing to try to stop the violence.

The three men face prison terms.

The death of African American Floyd on May 25, 2020 in a brutal police operation in Minneapolis triggered demonstrations against racism and police violence in the United States.

Videos document how police officers pushed the unarmed man to the ground.

White officer Derek Chauvin pressed his knee on Floyd's neck for a good nine minutes while Floyd begged him to breathe.

His colleagues Alexander Kueng, Tou Thao and Thomas Lane did not intervene despite Chauvin's actions.

According to the autopsy, Floyd lost consciousness and died.

At the end of April last year, a jury found Chauvin guilty of second-degree murder, among other things, in another trial.

A court in Minneapolis then sentenced him to 22 years and six months in prison.

A few months later, Chauvin pleaded guilty to the federal lawsuit against him, which faces an additional prison term.

The trial of the three ex-police officers has a signal effect in the United States.

The New York Times wrote that juries may be more willing to convict not only officers who kill people but also those who stand by.

Attorney General Merrick Garland said the verdict recognized that the ex-cops broke the constitution.

The verdict comes just days after three white men were convicted of hate crimes in the Ahmaud Arbery case.

The black man was killed while jogging in the state of Georgia.