Image copyright Reuters Image caption The protests have spread to other US cities, including Los Angeles

There has been enormous headline reaction in the world's media to the Ferguson protests, and many commentators have taken the opportunity to question America's credentials as a human rights champion.

European papers highlight inequalities in American society, and a South African commentator sees echoes of his country's own grim racial history.

China

The death of Michael Brown, whose killing sparked the unrest, is "a stark reminder for Uncle Sam that there are a lot of human rights violations on its own soil," says China's official news agency Xinhua.

"It should first fix its own problems before criticizing other countries."

Xinhua adds that few other countries are "as self-righteous and complacent as the United States when it comes to human rights issues, but the Ferguson tragedy is apparently a slap in the face".

Iran

Iran's Press TV dedicated all of its morning programmes to the Ferguson clashes, showing what appeared to be "live" video from the protests.

Press TV reported that attorneys for Mr Brown's family had said that the "grand jury process was rigged to clear the white officer" who shot him.

Image copyright E'temad Image caption Iranian reformist daily E'temad: "Anger and arson in Ferguson"

Image copyright Javan Image caption Iranian hard-line daily Javan: "Non-indictment of a white policeman; anger engulfs 90 American cities"

Iran's State TV said the grand jury decision "indicates the existence of racial discrimination in the USA".

The protests in Ferguson are also one of the top stories in the Iranian press.

The conservative newspaper Kayhan carried a collage of pictures from Ferguson, including a US flag being set on fire. Its headline said: "A rebellion in 90 American cities as a result of the non-indictment of the murderer policeman."

Javan, another hardline daily, carried a report headlined, "Non-indictment of a white policeman; anger engulfs 90 American cities".

Middle East

The story also features on the front pages of several Arab dailies.

In Egypt, Al-Wafd sums up the widely-expressed view in the headline "An uprising against racism in the USA".

Qatar's Al-Watan says US cities have been denouncing "lethal racism", and Syria's official Al-Thawrah newspaper notes that protests against police violence and racism are on the increase.

On social media, some Arabic-language posts have been mocking the US government and even gloating over its mishandling of the case. The Twitter hashtag #USAprotests in Arabic has been used more than 4,000 times since Tuesday.

Russia

The #Ferguson hashtag is also among the top 10 Twitter trends in Russia, and press articles have drawn parallels between Ferguson and the Maidan protests in Ukraine.

Image copyright Izvestiya Image caption Russian newspaper Izvestiya compares the US to Ukraine and how government protests in Kiev's Maidan Square began the ongoing unrest in the east of Ukraine.

"Barack Obama gets his own Maidan", the pro-Kremlin daily Izvestiya says.

Ren TV plays on the racial aspect of the Ferguson protests and also brings in the Ukrainian crisis, describing the demonstrations as a "colour revolution" and "an attempt to start a civil war in the US".

Europe

Ferguson is also a front-page story in the German press.

Uwe Schmitt, the former Washington correspondent for Germany's centre-right daily Die Welt, writes it is a "predictable explosion" given the juxtaposition of a "grotesquely over-armed police force" with a black community "untouched by economic recovery".

He accuses many Americans of "self-delusion" when they ask how such violence can recur again and again, while abroad "people shake their heads unsurprised, either in mourning or glee".

Image copyright Die Welt / Liberation Image caption "America's ordeal" and "United States injustice" - European papers provide more of the same sentiment, of problems at home for the US

An editorial in France's Liberation newspaper says: "Ferguson is a long way from being the post-racial America dreamed of by Barack Obama."

In Spain, Pere Vilanova writes in El Periodico that "perhaps the symbolic value of the election of a black man as president in 2008 has been overestimated and inter-communal wounds will never be healed".

In Italy, La Stampa's New York correspondent Paolo Mastrolilli says the discussion has become one about the race problem "connected to inequality and economic disparity". He notes that some of the white demonstrators in New York and Los Angeles wanted to broaden the debate in that direction.

South Africa

Writing in South Africa's Daily Maverick, Richard Poplak finds that images of officers facing off against enraged citizens show "an American city aping South African archival footage".

"It's a reminder that in divided countries, with histories of institutionalized racism, reconciliation without actually reconciling... justice is not just impossible, but a massive cover-up, a ruse used by power."

BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring on Twitter and Facebook.