Facebook Inc on Friday reinstated a photo of a naked girl fleeing a napalm attack during the American war in Vietham, after a public outcry over its removal of the image including harsh criticism from Norway's prime minister.

In a clash between a democratically elected leader and the social media giant over how to patrol the Internet, Norway 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.

"After hearing from our community, we looked again at how our Community Standards were applied in this case," Facebook said in a later statement, adding it recognized "the history and global importance of this image in documenting a particular moment in time."

Solberg posted the iconic "Napalm Girl" news photograph on her Facebook page after the company had deleted it from sites of Norwegian authors and the daily Aftenposten. Facebook had also removed the photo from the page of the woman who had been photographed as a girl.

Captured by Pulitzer Prize-winner Nick Ut of the Associated Press, the image of screaming children running from a napalm attack shows a naked nine-year-old girl at its center.

Solberg said Facebook's ban put unacceptable limits on freedom of speech. "They must see the difference between editing out child pornography and editing out history," she told Reuters.

"It's perfectly possible for a company like Facebook to sort this out. Otherwise we risk more censorship," she said.

Protesting Facebook's move, Solberg re-posted the photo with a black square covering the naked girl, and published a range of other historic images blacking over faces of people such as Ronald Reagan or Winston Churchill.

Solberg wrote on her Facebook account: "I want my children and other children to grow up in a society where history is taught as it was."

Aftenposten splashed the Vietnam photograph across its front page on Friday, next to a large Facebook logo, and wrote a front-page editorial headlined "Dear Mark Zuckerberg", saying the social network was undermining democracy.

Earlier, Facebook said in a statement its rules were more blunt than the company itself would prefer, adding that restrictions on nudity were necessary on a global platform.

Norway is a big investor in Facebook. Its $891 billion sovereign wealth fund, the world's biggest, had a stake of 0.52 percent in Facebook worth $1.54 billion at the start of 2016.

Solberg told Reuters she intended to maintain her Facebook account.

($1 = 8.2667 Norwegian crowns)