This is the terrifying moment police allegedly use a banned sonic cannon to stampede thousands of protestors at an anti-government rally in Serbia.
More than 100,000 demonstrators had besieged government buildings in the capital Belgrade in a mass uprising against government corruption on 15th March.
Now new video footage appearing on social media seems to show how riot police allegedly deployed a forbidden sonic weapon to attack the protestors.
In one clip, thousands of rally-goers are seen filling the city until without warning a deafening roar rips through the streets.
Panicked, the screaming protesters flee heading to the pavements and the shelter of shops as the footage comes to an end.
Experts say that sonic canons can emit up to 160 decibels, roughly equivalent to standing next to a rocket launch or a shotgun blast.
Human ears have a pain threshold of 120-130 decibels and anything above that is incredibly painful.
Military analyst Aleksandar Radic told local media: "The biggest problem is – who came up with the idea to use such a weapon?
"In a situation when all the protesters were calm, when a fifteen-minute silence was going on, the weapon was used.
"The only goal of that act is a brutal display of force, proof of arrogance, and the motive is hatred towards one’s own people."
And although Serbia's Interior Minister Ivica Dacic has said no sonic canon was used, he has not denied that security forces have one.
One law student named only as Aleksandar told local media: "The President and all the authorities of the Ministry of Interior can say whatever they want.
"They can continue to deceive us, but I think that all of us who were there felt it.
"They were truly scenes of horror."
Local MP Zdravko Ponos also told Serbian media that a sonic canon had been deployed.
He said: "The reaction of the crowd, that they felt as if something had passed through them, was a consequence of the use of sound, with the aim of scaring them.
"The use of this weapon can also harm health, and the fact that it was used is a complete scandal."