Police spokesman Thomas Keiblinger confirmed that the incident took place on Thursday evening and that the teenager threatened to shoot the owner of the bar and the DJ if they didn't hand over his missing phone - which he believed had been stolen.
The out-of-control youth was arrested shortly afterwards. The weapon turned out to be a replica gun and police found the missing phone in the man's jacket pocket.
A waitress at the bar called the police shortly after 11pm, and they were soon at the premises in Vienna's Ottakringer Strasse.
Witnesses told officers that the man had become angry when he couldn't find his phone and that he grabbed the computer mouse out of the DJ's hand and abruptly turned the music off. Then he took a gun out of his pocket and aimed it at the ceiling, yelling “nobody leaves this place!”. There were around 25 people in the bar at the time.
The 19-year-old then ordered the owner of the bar to come outside with him, telling him he was going to shoot him. Once outside, the owner was able to calm him down and young man tucked the gun into the waistband of his trousers, and went back into the bar. At this point several police cars arrived, including an armed WEGA unit. "He has disarmed and did not resist arrest,” Keiblinger said. Police found his mobile phone when they searched his jacket.
The 19-year-old told police he had only brandished the weapon in “self-defence” after he got into an argument with other drinkers in the bar. However, his fellow guests said this wasn't the case and that he was the only person being aggressive. He was arrested on suspicion of making serious threats, given a provisional firearms ban, and is currently in police custody.