Three men clad in black and another one in a white T-shirt storm into a supermarket, drag a refugee outside and zip-tie him to a tree. That's not a scene from a bad action movie but a real-life act of violence that took place in the small eastern German town of Arnsdorf close to Dresden.

The incident was filmed, with the video first appearing online on May 31, but according to a police report, it already occurred on May 21.

The asylum applicant, a 21-year-old man from Iraq, is seen in the video holding a bottle of wine, talking at the cashier. According to the police report, he had bought a phone card from the "Netto" store the day before and had returned twice on May 21 in the afternoon because of problems with activating it. The police were called both times and escorted the man back to Arnsdorf's psychiatric hospital, where he is a patient.

From what can be seen in the video, it's clear that the Iraqi and the female "Netto" employee cannot communicate because of the language barrier. She is asking him to put down the bottle, he doesn't react and keeps talking at her insistently. A voice can be heard suggesting to call the police.

But instead of uniformed officers, the four vigilantes appear. They beat up the mentally ill man, yelling "What do you want here? You pig!" and pull him out of the store. Before the video cuts off, a woman is head saying "It's a shame we need a neighborhood watch group, isn't it?"

Vigilantes not processed by police

Outside the supermarket, the vigilantes tied the refugee to a tree with cable connectors, according to the police report. However, there's only a video from inside the store.

"The responsible men said they were keeping the man there to ward off a dangerous situation and wanted to prevent him from fleeing the scene," the report reads. "Officers asked the group to leave the scene."

Police did not collect the men's personal details when they arrived because of the "tricky situation," a police spokesman told German tabloid "Bild." They are now looking for witnesses that have information on the men, who are suspected of illegal restraint. Police are also investigating whether the Iraqi man threatened the cashier.

The video has attracted a lot of attention in social networks like Facebook and Twitter. One tweet says people should say "Thank you" to the men who beat up the refugee.

On Facebook, the video has mainly been shared in rightwing-leaning groups and attracted many xenophobic and anti-refugee comments.

"Kudos to the neighborhood watch," one user commented on the video shared on the Facebook page "Those who don't love Germany should leave it." "It's sad that this is necessary. This vermin believes it can do whatever it wants around here," she wrote.

"Long live the neighborhood watch!," another user commented. "Whatever the state can't manage, we'll just do ourselves. Keep going."

Violence 'not condoned by Netto'

On the "Netto" store Facebook page, a user shared the video on Wednesday, writing that "employees who call a 'neighborhood watch group' instead of the police should be fired."

A store representative reacted within an hour.

"We take this incident very seriously," the Netto Facebook Team commented on the user's post. "After talking to our employees, it was determined that the men wearing black T-shirts… were not called by a Netto employee… The approach seen in the video is counter to our company rules and not condoned by Netto in any way."

As of Thursday afternoon, #Arnsdorf was trending on Twitter in Germany. The Left Party, which is in the opposition in Saxony, wrote that it condemned the act of "self-administered justice."

The tweet reads "Outside Saxony, a group of men who beat and shove a mentally ill man and tie him to a tree with cable connectors is called a 'mob,' not a 'neighborhood watch group.'"

One of the vigilantes tying the Iraqi man to a tree is said to be Arnsdorf council member Detlef Oelsner from the conservative CDU, according to media reports.

"We showed moral courage and would have done that to any other person, also if that person would have been German," Oelsner, who ran for mayor of Arnsdorf last year and lost, told the regional newspaper "Sächsische Zeitung."

Monika Lazar, a Green Party politician from Saxony, who's a member of Germany's parliament, the Bundestag, asked on Twitter whether Saxony's CDU now condoned self-administered justice.