Serbian officials denied using a military-grade sonic weapon against protesters at a massive anti-government rally in Belgrade.

Opposition groups claim the banned acoustic device, which causes pain and disorientation, was deployed and plan to file legal charges.

The protest, sparked by a deadly train station collapse, drew over 100,000 people demanding accountability.

Footage shows a sudden whooshing sound causing panic, the Associated Press has reported.

Serbian authorities dismissed the allegations, with President Vucic calling for an investigation into both the claims and those spreading them.

Written by B.C. Begley