The Ferguson incident in the United States, which has sparked persisting protests, has triggered widespread criticism in Europe.
Spanish Cadena Ser radio highlighted the fact that blacks account for 93 percent of all arrests in Ferguson although they make up only two-thirds of the whole population.
According to figures from about 1,600 police departments in the United States, black people are seven times more likely to end up in prison than whites, the radio noted.
The center-left El Pais newspaper said Ferguson, a town with just 20,000 inhabitants, is "the traumas of (Barack) Obama's America."
The newspaper mentioned that Ferguson was founded by slave owners and "discriminatory attitudes persist and have crushed the hopes that Obama's arrival in the White House brought in 2009."
French Justice Minister Christiane Taubira posted three tweets on Tuesday questioning the decision of American justice that the officer who shot dead Michael Brown will not be charged.
"It is clear that, when the frustration is so strong, so deep, so lasting and so massive, the confidence in these institutions has to be questioned," she continued to express her concerns on France Info.
Le Figaro newspaper said the chaos in Ferguson will force Obama to face the racial issues in the country.
"It destroys the hopes of those who had naively believed that the election of the first black president in the United States history would bring the country into a 'post-racial' era. Five and a half years after his election to the White House, Barack Obama is caught by the black question," said the French newspaper.
In London, around 1,500 people joined protests at the U.S. embassy on Wednesday to support the family of Brown, who was shot dead by white police officer Darren Wilson.
The protests, initiated by Britain's anti-racism organization Stand Up To Racism, lasted over three hours, after which thousands of people took part in an impromptu march down Oxford Street.
Diane Abbott, a member of the British Parliament and supporter of the protest, said: "My deepest sympathies go out to the family of Mike Brown. Not only have they lost a loved one but following the grand jury's decision they no doubt feel the strongest sense of injustice, which can only make their pain worse."
"The anger and disruption that has already followed this decision extends beyond the killing of Mike right to the root of long-standing issues with the criminal justice system," said Abbott.
On Wednesday, another fatal police shooting came under spotlight as a surveillance footage showed a 12-year-old boy, who was playing with a fake gun in a park in Cleveland, was shot dead by a patrolling police officer.
"Time and time again no one is held accountable. When yet another unarmed young black man is killed and it is 'lawful'," said Abbott. "It can be no surprise that black people are questioning how much value these same laws place on their lives."
Rahul Patel, an anti-racist activist, said it is necessary to let the United States to be aware that people from around the world stand against this injustice.
"We must challenge racism against black communities in all forms, as racist attacks increase unless we do so," said Patel. "We must challenge institutional racism so that the police don't have the license to act without impunity."
After the decision not to pursue charges against the policeman, people feel that there is no other way than demonstration to express their emotions, said Benita Heiskanen, associate professor on American Studies at the University of Turku, in an interview with Finnish national broadcaster YLE.
Heiskanen said Obama's election as president did not change racial attitudes toward African Americans. In practice, the black and white residential areas are still highly segregated. "In practice, the situation has not changed," said Heiskanen.