Did Serbia use sonic weapons to disperse protesters?
Serbian security forces recently used a widely banned military-grade sonic weapon to disperse crowds who have been demonstrating in the streets of Belgrade for several days. Although Serbia has not denied having the acoustic device in its arsenal, Serbian officials have denied using it, and the opposition will file charges before the European Court of Human Rights (ECHR) and domestic courts against those who ordered the attack.
Serbian citizens have been demonstrating en masse in the streets of Belgrade and other cities for several days to protest against the corruption of President Aleksandar Vučić's government. Overwhelmed by the protests, Serbian security forces have used unconventional weapons to disperse the crowd in recent hours.
The images have spread like wildfire on social media and show what the use of sonic weapons can be like, capable of emitting powerful waves and sounds that frighten and stun people. Their use is highly controversial as, if used incorrectly, they can cause serious damage to the auditory system.
Serbian police and state forces have used such weapons in Belgrade in recent hours during the fifteen minutes of silence in honor of the fifteen victims of the Novi Sad train station bombing. In the images, you can see streets completely congested with protesters. Suddenly, moments after the sonic weapons were activated, the crowd began running screaming toward the sides of the streets, which cleared within seconds. What causes such a reaction?
Police units often use trucks equipped with water cannons, tear gas, rubber bullets, and other equipment to break up protests and restore public order. However, in recent years new techniques based on directed energy weapons have emerged. Like the previous techniques, they are not lethal, but they are more effective and offer the advantage of not requiring as much exposure for officers and not causing serious injuries like rubber bullets.
Among these sonic weapons, there is evidence of the Active Denial System (ADS), which uses the emission of electromagnetic waves, and the Long-Range Acoustic Device (LRAD), which is based on the projection of mechanical waves, that is, sound.
The first of these involves firing a high-power beam (about 100 kW) at a frequency of 95 GHz, within the microwave band. This system, with a wavelength of 3.2 mm, works similarly to a microwave, exciting the water and fat molecules located in the skin, heating them.
According to a spokesperson for the U.S. Air Force Laboratory (AFRL), a person under the influence of this system feels their skin heat up, giving the sensation of burning. However, once the radiation area is removed, the skin returns to its natural state and the pain disappears.
The LRAD, for its part, is a sonic cannon that produces a tone at a frequency of 2 kHz with a power of more than 135 dB. This sound is perfectly audible to humans, given that the frequency range perceived by the ear is between 20 Hz and 20 kHz. However, not everyone is able to perceive the higher-pitched sounds, between 16 and 20 kHz.
LRAD systems are in service in at least 20 countries. In Spain, there is evidence of the use of a similar device in 2014 by the Mossos d'Esquadra (Catalan police) during marches in support of the Burgos neighborhood of Gamonal in Barcelona. These systems are also being used by navies and shipping companies to prevent pirate attacks.
In the case of Serbia, all indications are that a system similar to the LRAD was used, as some of the videos show a high-pitched sound similar to that recorded during the 2009 Pittsburgh riots (the first use of this weapon on US soil) during the G-20 summit. According to Serbian media, the country's Interior Ministry acquired them several years ago.
While these techniques do not harm the health of protesters, their stunning effect can cause stampedes, leading to very dangerous situations, such as being crushed by crowds, which is life-threatening.
Regardless of their use, these systems allow police forces to quickly and effectively break up unauthorized demonstrations or assemblies, restoring public order without endangering the physical safety of officers or protesters. However, its use remains highly controversial.