Moroccan authorities on Thursday reportedly arrested four suspected jihadis for hacking two Scandinavian backpackers to death and beheading one of them in Morocco’s Atlas Mountains. The suspects allegedly made a video pledging allegiance to the Islamic State (ISIS/ISIL) before the murders.

One of the unnamed hikers who found the bodies reportedly said, “It was horrible. They were broken. We warned everyone we saw … not to go up there. I did not want more to see what we had seen … It was a big shock, we’re thinking about it all day. It makes you think about what’s important in life.”

Danish intelligence officials believe ISIS “may be” behind the attack.

“The video and preliminary investigation according to the Moroccan authorities indicate that the killings may be related to the terrorist organization Islamic State,” the Danish intelligence service declared in a statement, Reuters reports.

“This is a case of an unusually bestial killing of two totally innocent young women,” the Danish agency added.

Danish Prime Minister Lars Loekke Rasmussen and Norwegian Prime Minister Erna Solberg condemned the attack.

“What should have been a holiday trip turned into a nightmare” for the women, Rasmussen told reporters Thursday, adding, “We do not know the circumstances, but a lot suggests that the brutal killing was an act of terror, and there’s a video on social media.”

The murders were “a brutal and senseless attack that we condemn,” Solberg added.

Rasmussen described the killings as “an act of terror,” adding, “There are still dark forces that want to fight our values” and “we must not give in.”

Mustapha El Khalfi, a spokesman for the Moroccan government, also condemned “this terrorist, criminal act.”

“It is an unacceptable act that does not fit with the values and traditions of Moroccan people nor the traditions of the area where the crime happened,” Khalfi declared on Thursday. “It is a denounced, condemned act.”

Moroccan officials identified the victims as Louisa Vesterager Jespersen, 24, from Denmark, and Maren Ueland, 28, from Norway.

The suspects reportedly disseminated footage of the horrific crime on social media.

Australia’s News outlet notes, “The footage shows a blonde woman screaming while a man cuts her neck with what appears to be a sharp kitchen knife. One of the women was decapitated, and the other was found dead with a severe neck wound. One body was found inside a tent by French hikers and the other just outside.”

The Telegraph reveals that Morocco ’s general prosecutor confirmed the authenticity of the footage circulating on social media in which the four suspects also threatened to carry out attacks on behalf of ISIS.

“Investigations showed that the video was made last week before the killing of the two women, Danish and Norwegian tourists who were trekking in the Atlas Mountains,” the newspaper added.

Boubker Sabik, a spokesman for Moroccan national security, reportedly revealed that authorities detained one of the suspects on Tuesday and the three others on Thursday.

“Authorities have said no one is being sought besides the four in custody,” the Telegraph notes, adding, “Morocco is generally considered safe for tourists but has battled with Islamic extremism for years. More than a thousand Moroccans are believed to have joined the Islamic State group.”

An anonymous Moroccan national security official identified the three suspects arrested on Thursday to the Associated Press (AP) as Abdessamad Ejjoud, born in 1993; Younes Ouziad, born in 1991; and Rashid Aftati, born in 1986.