Moroccans held vigils in Rabat to mark the deaths of two Scandinavian tourists, who were found dead in the Atlas Mountains on Monday.

Some participants laid flowers and lit candles at the Norwegian embassy and later, the Danish embassy.

Others raised placards saying "sorry" while condemning the killing of women.

Louisa Vesterager Jespersen, 24, from Denmark, and Maren Ueland, 28, from Norway were found in the Atlas Mountains, on the way to Toubkal, North Africa's highest peak and a popular hiking destination.

Louisa Vesterager Jespersen Bovec Sports Center Archive/via REUTERS

Norwegian Maren Ueland Private Handout/NTB Scanpix/via REUTERS

Moroccan authorities have said four suspects arrested over the murder had pledged allegiance to Islamic State in a video posted on social media before the killings. The women were found with knife wounds to the neck, Morocco said.

A separate video of the actual deaths, also on social media, was likely to be real, Norwegian police said.

"When it comes to the assessment of the video that purportedly shows the killings, there is still a certain amount of technical analysis and assessment to be done," Norway's National Crime Investigation Service said in a statement.

"We still believe, however, that we have grounds to say that so far, there is nothing concrete to show that this video is not real."