OSLO: Facebook was confronted Friday with fierce indignation in Norway as the nation's top newspaper, the prime minister and users voiced outrage over the network's decision to censor a historic Vietnam War photo.

Facebook has been deleting from users' pages, including that of Norwegian Prime Minister Erna Solberg, the 1972 picture of a naked Vietnamese girl running from a napalm attack, one of the war's defining images.

Taken by Vietnamese photographer Nick Ut Cong Huynh for Associated Press, the picture was honoured with the Pulitzer Prize.

“Facebook is taking the wrong road when it censors photos like this. This contributes to blocking freedom of expression,” the prime minister wrote on her Facebook page early Friday, in a comment that quickly received thousands of “likes”.

The affair began several weeks ago after Norwegian author Tom Egeland published a post about war photos, illustrated by the iconic picture. It was promptly deleted by Facebook.

Egeland's fans rose to his defence and published the photo, posts which Facebook also deleted in line with its rules barring nudity.

In recent days, Facebook has continued to remove the photo and even suspended the accounts of other Norwegians who posted it.

Facebook's moves have sparked fierce reactions in Norway, an ardent defender of civil liberties.

“I appreciate the work done by Facebook and other media to stop images and content showing physical abuse and violence. It's important that we all contribute to the fight against violence and physical abuse of children,” the prime minister's Facebook post said.

That post was deleted at midday, with the prime minister's office saying later Facebook had removed it. Solberg re-posted the picture several hours later, this time with the nudity blacked out in protest and a plea to Facebook to “review its censorship policy and assume the responsibility befitting of a large company with a broad communication platform.”

Front page photo

Norway's biggest daily Aftenposten also shot back against Facebook's censorship by publishing the photo on its print front page on Friday, under Facebook's logo, accompanied by a two-page open letter to Facebook founder Mark Zuckerberg.

“I write you this letter because I'm concerned by the fact that the biggest media in the world is limiting freedoms instead of trying to broaden them, and because this is happening in a sometimes authoritarian fashion,” editor-in-chief Espen Egil Hansen wrote under the headline “Dear Mark.”

Aftenposten had also published the picture on its Facebook page several days previously. Facebook had asked it to take down the picture, but then deleted it before Aftenposten editors could respond to Facebook's request.

“I'm afraid we're becoming a society where the lowest common denominator determines what is shocking to the global population,” Hansen told AFP.

“The information has to be as acceptable in a small village in Pakistan as in an intellectual milieu in Paris. This lowest common denominator is a very dangerous mechanism when it is implemented by the most influential editor-in-chief in the world,” he said in reference to Zuckerberg.

The affair has taken on such proportions that the Norwegian Press Federation has asked the country's powerful pension fund, the world's largest sovereign wealth fund, to examine whether the censorship practice was in line with its ethical criteria for investments.

At the end of 2015, the fund owned 0.52 percent of Facebook.

This is not the first time Facebook has been accused of censorship, which is problematic because of its growing importance as a key channel of information for many people.

Facebook has in the past blocked several artworks.

The company is to go on trial in France after a schoolteacher accused it of censorship for blocking his account after he posted a photo of a painting by Gustave Courbet called “L'Origine du monde” (The Origin of the World) that shows a woman's genitals.

And earlier this year, a Danish lawmaker also complained that Facebook had removed her picture of the Copenhagen statue of the Little Mermaid because of its nudity rules.