Hundreds of people brought flowers and shed tears on Saturday in a show of opposition to violence and religious extremism.

They were honouring 28-year-old Norwegian Maren Ueland and 24-year-old Louisa Vesterager Jespersen, whose bodies were found Monday. Authorities say the hikers were killed by four men affiliated with the Islamic State group.

The killings shocked Moroccans as much as those in Denmark and Norway.

"I am deeply touched by the kind reactions of the Moroccan people after the tragic event," the Norwegian ambassador to Morocco, Merethe Nergaard, said in a statement.

The mourners included ordinary Moroccans joined by politicians, artists and activists. Some held banners saying "Sorry" and condemned the brutal killing, which is unusual in Morocco and revived fears of terrorism.

"Words cannot describe this barbaric crime," said Khalil Bensalmi, in his fifties, who came to the vigil with his two daughters. "This doesn't at all represent Moroccan society or its pacifist culture."

The group first held a vigil in front of the Norwegian Embassy, read a letter in memory of the two women, then held a moment of silence. Many attendees cried. They then quietly departed to the Danish Embassy, where again tears were shed, and candles were lit in honor of the two women, university students passionate about the outdoors.

A torch-lit parade was held in Ueland's hometown in Norway on Friday.

The killings marked the first terrorist attack to hit Morocco since 2011, when a suicide bomber detonated in Marrakech and killed 16 people.

More than 1000 Moroccans have joined IS in recent years, and Moroccan authorities arrested 20 cells with terrorist affiliations between 2017 and 2018.

The hikers' killings triggered fear among Moroccans of a renewed terrorist threat.

Thirteen men have been detained in the investigation.

Australian Associated Press