In a clash between a democratically elected leader and the social media giant over how to patrol the internet, prime minister Erna Solberg said Facebook was editing history by erasing images of the iconic 1972 "Napalm Girl" photograph, which showed children running from a bombed village.

The company initially said the photo violated its Community Standards barring child nudity on the site.

Earlier a furious Norwegian newspaper had taken Facebook chief executive Mark Zuckerberg to task for "abusing his power" as the world's most powerful editor.

Espen Egil Hansen, editor-in-chief of the Aftenposten, the country's biggest newspaper, published a long tirade against Mr Zuckerberg after receiving an email from Facebook saying the image contravened the site's rules.

Facebook had also suspended Norwegian author and journalist Tom Egeland after he shared the image on the social networkseveral weeks ago as part of a story on seven photographs that changed the history of warfare.

Aftenposten reported on that suspension and used the same photograph in its article, which it then shared on the newspaper's Facebook page.

But Facebook sent Aftenposten an email asking them to "remove or pixelise" the photograph.

"We place limitations on the display of nudity to limit the exposure of the different people using our platform to sensitive content," Facebook's letter said, adding that it allowed some exceptions for "content posted for educational, humorous or satirical purposes".

Less than 24 hours after sending the email, Facebook unilaterally deleted the article, and the image, from Aftenposten's Facebook page.

It also censored  Ms Solberg after she posted the photograph on her own Facebook page in solidarity.

Ms Solberg posted the picture on Friday morning but it was taken down just three hours later, Bloomberg reported.

The Terror of War, a photograph by Nick Ut showing nine-year-old Kim Phuc fleeing a napalm attack, won a Pulitzer prize and is considered one of history's most powerful war journalism images.

"Listen, Mark, this is serious," Mr Hansen wrote. "First you create rules that don't distinguish between child pornography and famous war photographs. Then you practice these rules without allowing space for good judgement.

"Finally you even censor criticism against and a discussion about the decision – and you punish the person who dares to voice criticism."

Mr Zuckerberg has denied that Facebook is a media company.

However Mr Hansen said that Mr Zuckerberg was "the world's most powerful editor" as Facebook was "offering us a great channel for distributing our content".

"You are restricting my room for exercising my editorial responsibility," Mr Hansen wrote.

"I think you are abusing your power and I find it hard to believe that you have thought it through thoroughly."

Free and independent media must sometimes publish unpleasant images, he said.

"If liberty means anything at all, British George Orwell wrote in the preface to Animal Farm, it means the right to tell people what they do not want to hear.

"Editors cannot live with you, Mark, as a master editor."

Rolv Erik Ryssdal, CEO of Schibsted Media Group, which owns the newspaper, told Fairfax Media it was "not acceptable" for Facebook to "stop Aftenposten from publishing one of the most important photos of our time".

"Facebook's censorship is an attack on the freedom of expression – and therefore on democracy," he said.

In an email to the newspaper, a Facebook spokeswoman said that while they recognised the image was iconic, it was hard to distinguish between cases where naked pictures of children should be allowed, and when they should not be.

"We are trying to find the right balance between people having the opportunity to express themselves, and maintaining a safe and respectful experience in our global community," the email said.

"Our solutions will not always be perfect, but we strive to further improve our policies and the way we enforce them."

In a statement to Fairfax Media, Facebook said it had "looked again at how our Community Standards were applied in this case".

"An image of a naked child would normally be presumed to violate our Community Standards, and in some countries might even qualify as child pornography," the statement said.

"In this case, we recognise the history and global importance of this image in documenting a particular moment in time. Because of its status as an iconic image of historical importance, the value of permitting sharing outweighs the value of protecting the community by removal, so we have decided to reinstate the image on Facebook where we are aware it has been removed.

"We will also adjust our review mechanisms to permit sharing of the image going forward. It will take some time to adjust these systems but the photo should be available for sharing in the coming days.

"We are always looking to improve our policies to make sure they both promote free expression and keep our community safe, and we will be engaging with publishers and other members of our global community on these important questions going forward."

In an email to Fairfax Media, Mr Ryssdal also disputed Mr Zuckerberg's claim that Facebook was not a media company, saying that the social media giant was taking more than $200 million from the Norwegian advertising market but – along with Google – paid "only crumbs in taxes back to society".

Facebook uses an anti-child exploitation software tool by Microsoft known as PhotoDNA which constantly crawls through its pages looking for, matching and deleting exploitative photos of children. It also reports them to child protection agencies.

Ms Solberg said Facebook's ban had put unacceptable limits on freedom of speech.

with Reuters