Three men have been arrested on suspicion of aggravated rape, after hundreds watched the alleged rape of a woman in Uppsala broadcast live on Facebook.

Witnesses say one of the men drew a gun and threatened viewers during the broadcast, and the arrival of police to the crime scene was also caught on camera, reports Swedish newspaper Upsala Nya Tidning.

Several people who contacted local media said the assault took place from 3.30 am, and was broadcast live on the page of a closed group on Facebook. Police were contacted by a number of witnesses who saw the attack unfold on the social media website.

Viewers say they watched as officers arrived at the scene where the attack had been taking place, after which the livestream to the apartment was finally shut off.

Police in the Swedish city confirmed the arrest of three young men for aggravated rape.

“He pulled off her clothes and lay on top of her”, said witness Josefine Lundgren of what she saw during the broadcast, upon seeing which she “immediately” called the police.

During the livestream one of the men pulled out a gun and threatened viewers, challenging them to come to the apartment from where the scenes were being filmed, the Ånge resident said.

“This is insane”, she told Expressen. “Only sick people could do such a thing … I hope these guys are ashamed, and that they sit and think about what they have done.”

On Flashback, Sweden’s largest internet forum, users who said they witnessed the alleged rape as it was broadcast identified the attackers as a group of men of Middle Eastern appearance.

Several posts on Flashback linked to what their authors say are screenshots from the livestream, one of which appears to show a police officer at the scene.

The forum’s first post relating to the attack says that during the broadcast, one of the men could be heard trying to persuade the alleged victim, who it describes as having been “totally numb and intoxicated”, to say she had not been raped.

Police in Uppsala refused to give details on the arrest, which Fria Tider reported took place just after 9 on Sunday morning.

“ Three people have been arrested but otherwise I can’t give any further details, duty officer Nina Dahlström told Upsala Nya Tidning.