Oslo: Norway’s Prime Minister Erna Solberg joined escalating protests over censorship by Facebook, posting the iconic Vietnam War picture of the “Napalm Girl” to her profile on the social media network.

Solberg’s post was the latest in a row over photographer Nick Ut’s Pulitzer-prize winning picture of a naked Vietnamese girl, Phan Thi Kim Phuc, running down a road after being injured in a napalm attack on her village in 1972.

The controversy started as Facebook removed the picture from thriller writer Tom Egeland’s profile because of its rules on nudity. Norwegian newspaper Aftenposten then joined in and published the picture on its Facebook page, which was also censored. The newspaper on Friday also published an open letter to the social media’s founder, Mark Zuckerberg, to protest the action.

“I appreciate the work of Facebook and other media to stop pictures and content showing abuse and violence,” Solberg said in a comment posted with the picture on Friday. “But Facebook gets it wrong when it censors pictures like these. It contributes to restricting the freedom of speech.”

Facebook is facing criticism over its regulation of content as it aims to find a universal standard to apply to its 1.7 billion monthly users, and bans on pornography prevent posting art or historic photographs like the one at the heart of the controversy in Norway.

Facebook is seeking to strike a balance between enabling free speech and “maintaining a safe and respectful experience for our global community,” it said.

“While we recognise that this photo is iconic, it’s difficult to create a distinction between allowing a photograph of a nude child in one instance and not others,” an unidentified Facebook spokesperson said in an emailed comment. “Our solutions won’t always be perfect, but we will continue to try to improve our policies and the ways in which we apply them.”

Solberg’s post, published at 8.10am local time in Oslo, the Norwegian capital, was still featured on her page as of 11.18am.