Maren Ueland and Louisa Jespersen, two Scandinavian tourists who were backpacking in Morocco, were accosted and murdered in their tent in what authorities are investigating as a terrorist attack. A horrific video has circulated online that appears to show the gruesome murder of one of the two women, and a second video shows the suspects pledging allegiance to ISIS, authorities say.

Some people have even posted the nightmarish video on the comment thread of one of the women’s mother’s Facebook page.

Both women – ages 24 and 28 – were discovered with knife wounds to the neck (although that doesn’t begin to describe the attack shown in the video), and the Danish prime minister has declared the slayings “bestial,” according to BBC. Moroccan government spokesman, Mustapha El Khalfi, described the killings to the Guardian as a “criminal and terrorist act.” The women were remembered by loved ones for their adventurous and caring spirits. Jespersen’s full name is Louisa Vesterager Jespersen.

“The video and preliminary investigation according to the Moroccan authorities indicate that the killings may be related to the terrorist organization Islamic State,” the intelligence service of Denmark said. However, authorities now say they don’t think the slayings were coordinated with ISIS, characterizing the suspects as lone wolf attackers.

Here’s what you need to know:

1. One of the Women May Have Been Beheaded & the Bodies Were Discovered by Hikers

The women died in a graphic and gruesome manner. According to news.com.au, both Ueland and Jespersen were backpackers, and one of the women may have been beheaded (that’s what the gruesome video shows).

“This is a brutal and meaningless attack on innocent people, which we react to with disgust and condemnation,” the Norwegian Prime Minister Erna Solberg said in a statement.

The women were “knifed and beheaded on camera while camping in the Atlas Mountains,” News.com.au reports, adding that one woman’s body was decapitated and the other had severe wounds to the neck.

A French hiker found the bodies, telling the Australian news site, “It was horrible. They were broken. We warned everyone we saw in Imlil 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.”

According to The Mirror, the Moroccan interior minister said only that the women had “signs of violence on their necks” that had been “caused by a cutting device.” The New York Post reports that, in addition to the ISIS ties, the attack might be sexually-motivated, and the men were camping in a tent nearby the women.

Seized evidence includes “four long knives, one of which still had traces of blood, a small prayer book, stones and a slingshot and three mobile phones,” ABC News reports.

2. A Horrific Video Appears to Show One of the Women Being Murdered as She Screams

Adding even more horror to the story, it’s possible that one of the slayings was captured on video. Norwegian police now say they think the video is real. “There is no concrete evidence indicating the video is not real,” Norway’s National Criminal Investigation Service said, according to CBS News, which adds that Moroccan authorities also believe a separate video showing the killers “pledging allegiance to ISIS” is real.

The women met their fate in Imlil, “a popular tourist destination at the foot of Mount Toubkal, the highest peak in North Africa,” according to Daily Star.

BBC reports that Denmark’s PET intelligence agency has confirmed that it is investigating the video, which says “this is in revenge for our brothers in Hajin” – a reference to a Syrian area controlled by ISIS. Authorities said they verified the video but then walked that back saying it was still being investigated, according to The Guardian. Some of the images were sent to the slain women’s friends and one of their mothers through social media.

Irene Ueland posted her daughter’s picture with a simple tribute: “❤️Maren vårs❤️ 23.11.1990 – 17.12.2018.” Irene Ueland’s comment thread underneath that photo has filled with more than 7,000 comments from people offering prayers, expressing anger, condemning the attack – and sharing images and videos of the sickening video that appears to show backpacker Jespersen being murdered.

“This is what those motherf*ckers did,” wrote one man who posted the video in Irene’s thread. Others chastised the man, with one writing, “This is the page of one of the girls´ mother! WHAT IS WRONG WITH YOU!!!”

“The footage shows a blonde woman screaming while a man cuts her neck with what appears to be a sharp kitchen knife,” according to News.com.au, which also reported that this woman was Jespersen. The awful video, which is still circulating on sites like 4Chan, shows blood pouring from the woman’s neck as a man hacks away at her neck with a large knife. In one frame, the head of a woman is seen on the floor completely severed from her body after the murderer carries it away from the body and places it in another spot on the floot. Horrifically, someone posted that video in the comment thread of one of the backpackers’ mother’s tribute post to her daughter on Facebook. It’s easily one of the most disturbing things a person could ever watch. If you’re considering trying to watch it – don’t. You’ll have nightmares for days. The woman being murdered is alive for the start of the beheading and briefly screams before going silent.

Daily Star says a man in the video also says “This is for Syria, here are the heads of your Gods.” Another phrase used in the video was “it’s Allah’s will” and the men are accused of filming a second video pledging allegiance to ISIS.

3. The Women Were College Students in Norway Who Enjoyed the Outdoors

Both women were college students in Norway. According to VG, they attended the University of Southeastern Norway. Jespersen was Danish.

“We have today received the bad message that two USN students at campus Bø were killed in Morocco,” Rector Petter Aasen said in a press release, according to VG. “What we know so far is that they were on a one month long private holiday in Morocco. Our thoughts now go to the families of the girls.” This is a video of Jespersen posted by a friend:

According to VG, Maren last communicated with her mother on Sunday, December 9, 2018, saying that things were good. On her Facebook page, Maren Ueland wrote that she was an environmental therapist at Bø municipality who “studied Outdoor life, culture and nature guidance at the University of Southeastern Norway” from 2017 to present and who lived in Bø i Telemark.

In 2017, an Australian woman posted a photo of Jespersen on Facebook and wrote, “A couple of days ago Cody and I were travelling down the coast when we saw this girl hitch hiking on the side of the road ! We picked her up and have travelled together the last couple of days ! Such a breath of fresh air having her around . We talked about our countries we lived in and the sites that have been visited . She is from Denmark . Let’s just say if we ever go to Denmark we will definitely be catching up again !!”

4. Jespersen’s Mother Remembered Her Daughter as Adventurous

Speaking to Denmark’s BT, Jespersen’s mother described her as “always happy and positive. She got the best in everyone.”

One woman who was in the area said she ran into the women before they died, telling VG, “On our way down to the car we met two girls in the 20’s. One was Norwegian and the other one was Danish. They were gentle and brought large backpacks. We had a nice conversation with the two.”

The women had decided to spend Christmas hiking in Morocco, according to BT.

A close friend of Jespersen posted a lengthy tribute to her on Facebook.

He posted this video:

The post reads in part: Thousands of candles can be lighted from a single candle You were that single candle Louisa. I’ve been very unsure of whether I wanted to post anything here. As soon as I press the button, I confirm to myself that this has really happened. In the last few nights, I’ve gone to bed and hoped that I wake up the morning after and everything was just a very bad dream. But here’s my letter to Louisa Vesterager Jespersen. Dear Amazing Lulu, Funny (at least you tried your best to be), full of energy, bundle of joy, inclusive, caring and thoughtful. These were just a few of your many amazing qualities. You were also known to be distracted, slow and clumsy. These qualities that made so many of us to scratch our head, but it was just these that made you unique and loved. You were so curious and everything fascinated you. I can’t even count how many times we were on a trip together and I turned around and you had disappeared, only to find you way behind me because you had to look closer to a beautiful flower, a view or something that the average person wouldn’t even notice. You saw beauty in every smallest detail. Louisa, I was so lucky to be your boyfriend for two years until this summer. We split up as best friends with tears in our eyes because we had realised that we didn’t love each other anymore. We both were very sorry, but agreed that it was the way it was. It breaks my heart that there is someone who would hurt you, you always saw the very best in people and you brought out the best in the people around you. (unless we were standing in the hallway and were late for something important). Your life may not have been long, but it was rich in experiences. If you wanted something, it was very difficult to stop you. You traveled around the world just as you would, you would not be limited by fear of all the dangers of the world. You did what you wanted and you were tough. You will live on in the heart of all the people you have met through the journey of your life. I carry you with me the rest of the way and take you up on the mountains and down the rivers you never had the opportunity to experience. You have a special place in my heart and it is reserved for you the rest of my hopefully long life. To make room for you in my heart, I also had to give you a part of mine. So a part of me died Monday morning, but it also means that part of me is with you wherever you are now. No matter how lonely you are, I’ll be there with your side and you with mine. I wish you good luck in your journey further wherever it takes you. I don’t say goodbye, but at reunion my friend ❤ Your Gleno

Another friend of Jespersen’s described how her “enthusiasm for life was only matched by her unforgettable laughter.”

5. Four Suspects Are Under Arrest & at Least One Has ISIS Ties

Arrest of 3 suspects following the murder of 2

Scandinavian tourists in #Morocco.

They should be delt with the strictest punishments available for comiting such a horrendous act.

Our thoughts are with the victims and their families.#Imlil #Maroc #ISIS pic.twitter.com/Xdyj0IiImj — Ouissal (@0uissal) December 20, 2018

According to VG, police arrested multiple men in the slayings. A press release from the Minister of the Interior in Morocco, reprinted by VG, said of the first apprehension: “The arrest was made this morning in Marakkesh. He is now questioned to determine what motives he may have had and to get details about the murder. The investigation will continue with the aim of identifying and arresting other potential suspects involved in the act.”

The suspects’ names are Abdessamad Ejjoud, Younes Ouaziad, Rachid El Afati, and Khayali Abderrahmane, ABC News reports, with Abderrahmane alleged to be the main suspect with ties to the Islamic State.

BT, which is a Danish news site, reported that Moroccan authorities “have stated that the case is being investigated as terror. The video and preliminary investigation, according to the Moroccan authorities, point out that the killings may be related to the terrorist organization IS.”

BT noted that “one person arrested in the case has a connection with a terrorist group” although Moroccan media had previously said there were four suspects and all might have Islamic State ties. Authorities said on December 20, 2018 that they had four suspects in custody, although some news stories put the number of suspects at three. One of the suspects is a carpenter and one a salesman.