The European Court of Human Rights (ECHR) has demanded that Serbia provide answers by March 31 regarding the alleged use of sonic weapons during a protest in Belgrade on March 15, according to a statement released by Serbian civil society organisations on March 25. 

The organisations, which filed a request on behalf of 47 Serbian citizens, revealed that the ECHR is seeking detailed information on the potential health consequences faced by individuals exposed to sonic or similar devices during the protest.

The protest on March 15, the largest in Serbia's history, was marred by disturbing footage of the crowd abruptly scattering during a 15-minute moment of silence for the 15 (now 16) victims of the Novi Sad tragedy. Several witnesses described hearing a sound similar to a passing train or plane, which caused widespread panic, distress and numerous reports of ear injuries.

Serbian authorities, who initially denied owning or using the sonic weapons at the protest, were forced to admit last week that a Long Range Acoustic Device (LRAD) was present in Belgrade on that day, after photo evidence emerged on social media. However, they have maintained that it was not used as a “sound cannon” against the protesters.

The Serbian prosecution has launched an investigation into the incident but has yet to offer an alternative explanation for the scenes witnessed during the protest. In the meantime, the Serbian government has invited both the FBI and Russia’s FSB to investigate.  

Following a meeting with EU officials this week, Serbian President Aleksandar Vucic said the government had "nothing to hide" and was prepared to demonstrate that the allegations of sonic weapon use were unfounded.

"We are ready to show everything and prove that the use of a sound cannon during the protests on March 15th was not carried out," Vucic stated on March 25, adding that the FSB would arrive within days, while FBI agents were expected in Belgrade within a week.

On March 26, Serbia's leading Russophile, Vice President Aleksandar Vulin, confirmed to the state broadcaster RTS that FSB experts would be arriving in Serbia soon to investigate the allegations.