WATCH: Tourist slayers in Morocco pledge allegiance to ISIS

A video surfaced on the internet on Thursday of the killers of two foreign tourists in Morocco pledging allegiance to ISIS.

The video was shared by social accounts close to the terrorist group.

One of the killers threatened to carry out other similar “operations” in Morocco.

The video shows the four men involved in the crime pledging allegiance to ISIS leader Abu Bakr al-Baghdadi, and acknowledging him as their prince.

Threatening with other operations, one of the killers said in the video: “Take care of your necks, we have planned what will not even cross your mind.”

Moroccan prosecution confirmed later on Thursday that the killers pledged allegiance to ISIS.

Moroccan authorities arrested three people on Thursday, bringing to four the number of suspects in the killing of two foreign tourists in the mountain village of Imlil in the province of El Haouz in the outskirts of the city of Marrakech, southern Morocco.

The counterterrorism office revealed that the arrest took place Thursday morning in the city of Marrakech in coordination with the police.

Previously Moroccan authorities said Wednesday, that the lone suspect arrested in the killing of two Scandinavian tourists in Morocco’s Atlas Mountains is connected to a terrorist group

Local media reported that the suspects had links to the ISIS group.

The women, who were from Denmark and Norway, were discovered stabbed in the neck Monday by other tourists, who alerted police, according to national media. Hiking in the area was temporarily suspended.

The killings have shocked Morocco, a popular tourist destination where such attacks on foreigners are extremely rare.

The Rabat public prosecutor’s office said in a statement Wednesday that the only captured suspect has affiliations to a terrorist group, without naming the group.

The suspect was arrested in Marrakech on Tuesday. Three other suspects have been identified and but are still on the run, a security official told The Associated Press. The official was not authorized to be publicly named.

The remote mountainous region where the women were found dead is 10 kilometers (6.2 miles) from the village of Imlil — often the starting point for treks to Mount Toubkal, North Africa’s highest peak.

Broadcaster 2M released photos and videos Wednesday of forensic investigators and others working around the women’s brightly colored tent on a rocky hillside. The broadcaster said the tent held food and belongings for three people, including an ID card.

Moroccan media outlets reported that investigators have video surveillance footage showing three suspects putting up a tent near the victims’ tent and leaving the area after the slaying.

Authorities in Denmark and Norway warned their citizens from hiking without local guides in Morocco after the killing. Danish police officials said Wednesday they sent an officer to Morocco to assist in the investigation.

Morocco is generally considered safe for tourists and is a key ally of the United States and Europe in the fight against terrorism. Morocco has struggled for years with sporadic Islamic extremism, and more than 1,000 Moroccans are believed to have joined the Islamic State group.

Media in Norway identified the Norwegian hiker as Maren Ueland, 28. The mayor of her family’s hometown of Time, Reinert Kverneland, told Norwegian broadcaster NRK that he informed relatives of Ueland’s slaying. The victim’s mother, Irene Ueland, told NRK her daughter had taken safety precautions before making the trip.

The Danish victim was identified by media in Denmark as Louisa Vesterager Jespersen, 24. Her mother, Helle Jespersen, told tabloid BT two police officers rang the doorbell Monday evening with the message that her daughter had been killed. She said the family had warned her against undertaking the journey.

The University of South-Eastern Norway said on its website that both women were studying to earn bachelor’s degrees in outdoor life, culture and ecophilosophy. They attended a campus in Boe, southern Norway and west of Oslo.

“What we know is that they were on a monthlong, private holiday in Morocco. Our thoughts go to the families,” the university said on its home page, adding flags were flown at half-staff in their memory Tuesday.

with the Assiciated Press