A migrant mob caused mass panic on the underground after they began to shout "Allahu Akbar" and started firing guns in the carriage.
The incident happened in the Austrian capital of Vienna on Monday afternoon, leaving people terrified even though it turned out the guns were only firing plastic pellets.
Local media reported that four migrant teenagers were screaming the religious chant in Arabic and waving and firing guns - allegedly airsoft guns which are replica weapons used in airsoft sports.
Amer Albayati was one of the witnesses of the terror scare in a carriage on the U3-line near the Schweglerstrasse station.
The Austrian-Iraqi journalist and terrorism expert said that passengers panicked and were trying to get as far away as possible from the screaming teenagers.
Yet one brave passenger tried to overpower the migrant mob and somehow managed to kick the four out of the train for a short while at the Schweglergasse station.
But the group managed to get on again, and left two stops later at the Zieglergasse station.
The police are currently investigating the matter and are searching for the four youngsters aged between 10 and 16 years old, according to police spokesman Thomas Keiblinger.
Spokesman of the Vienna public transport services Daniel Amann said: "We have safety precautions on the train and on the platforms for precisely those incidents where passengers are not feeling secure."
He explained that passengers should not be afraid to use emergency intercom devices, which are present in metro carriages as well as on platforms, in emergencies like this.
It is not the first mass panic which has broken out in Austria after migrants shouted "Allahu Akbar".
In August, shouts of "Allahu Akbar" by Turkish protestors who attacked a Kurdish group caused widespread panic among masses of protestors and city centre shoppers.
Video footage of the stampede has emerged where people are seen fleeing the streets after the Islamic shouts were heard.
In the panic, the outdoor cafe of the traditional Viennese confectionery shop ‘Aida’ was devastated, according to local media.
In September, a Turkish migrant attempted to drive into a crowd of pedestrians while shouting "Allahu akbar". No one was injured in the attack.