On 29 April 2025, the European Court of Human Rights (ECtHR or the Court) granted part of the applicants’ requests to issue an interim measure in the case of Đorović and Others v. Serbia (App.no. 8904/25). The case involves the alleged use of a sonic weapon for crowd control by the authorities at demonstrations and the concern that it could be used at future demonstrations. In this contribution, I argue that at this point, the decision of the Court to grant interim measures was justified while we wait to see what will be written down in the application and subsequently what decision will be delivered by the Court. Moreover, the contribution discusses the lack of legal basis for the possible use of these kinds of weapons in Serbian legislation and the latest published report from the investigation conducted by the Russian FSB.
Context and content of the request for the interim measure
For five months and more, students across Serbia have been demanding that the institutions act in accordance with the rule of law and prosecute those responsible for the railway station collapse in Novi Sad in November 2024. They are blockading universities, and their protests are supported by large sections of the population.
On 15 March 2025, the applicants (47 Serbian nationals) took part in a protest in Belgrade. While observing 15 minutes of silence in memory of those who had died following the collapse of the canopy at Novi Sad train station in November 2024, at around 7 p.m., loud sounds and airwaves disrupted the demonstration.
The applicants, as described in their own words, experienced intense instinctive fear, panic, shock, accelerated heartbeat, trembling, hearing problems, vomiting, nausea, tachycardia, and similar symptoms. Some of them sustained physical injuries due to the panic. People who were on the demonstrations described how it started like a human stampede; people were running, and then they started falling, screaming, and panicking while they could not see anything. Hundreds of witnesses described a sound akin to a passing plane or a train descending on them, which caused significant distress, panic, and numerous injuries. Up to 4,000 people reported their experiences of the incident, and many of them sought medical attention even in the days after the demonstrations for ongoing symptoms. This has sparked a debate over the use of sonic or acoustic weapons, which authorities maintain that they were not employed, while students, the non-governmental sector, and the opposition insist on determining what transpired, what type of weapon was used, and under whose orders.
The applicants in the request for interim measures, had requested that the Court issue an interim measure that the Serbian authorities would (i) prevent use of sonic weapons in such circumstances; (ii) prevent criminal prosecution of those who take part in public debate on the use of a sonic weapon on 15 March 2025; and (iii) conduct an effective investigation into the allegations that a sonic weapon had been used. The Court indicated to the Government that it should prevent any use of sound devices for crowd control.
On 24 March 2025, the applicants requested that the Court indicate, in particular, that the Serbian authorities prevent using such means against demonstrators in future protests. The Court (a Chamber of seven judges) decided to issue an interim measure. Concerning the applicants’ request that the Court indicate that the State should prevent the use of sonic weapons or similar devices at future protests by the State and/or non-state actors, the Court indicated to the Government, until further notice, that any use of sound devices for crowd control (other than for communication purposes) must be prevented in the future. It noted that use of such weapons for crowd control was unlawful in Serbia and, in particular, potentially serious health effects that could be caused to a large number of persons. This request was granted in accordance with Rule 39 from the Rules of Court under which the Court may, in exceptional circumstances, whether at the request of a party or any other person concerned, or on its own motion, indicate to the parties any interim measure that it considers should be adopted. Such measures, applicable in cases of imminent risk of irreparable harm to a Convention right, which, on account of their nature, would not be susceptible to reparation, restoration, or adequate compensation, may be adopted where necessary in the interests of the parties or the proper conduct of the proceedings. Although the Court reiterated that the decision did not mean it had taken any position as to whether use of sonic weapons had occurred on 15 March 2025, with the granting the interim measure, the Court might have thought that there was a prima facie case that a sonic weapon was actually used or could be used again, and in order to prevent possible use in future decided to grant the interim measure until deciding upon the case.
What are sonic weapons?
Acoustic (sonic) weapons aim to use the propagation of sound a variation in pressure that travels through a fluid medium (such as air) to affect a target. Most of the acoustic weapons that have been speculated upon are based on either ultrasound, low frequencies or infrasound deployed at high levels. Although they are often branded as ‘non-lethal’ or ‘less lethal’, acoustic devices are open to the same questions and criticisms levelled against other technologies given that label and their use in conjunction with kinetic weapons actually increases the risk of death.
Sonic weapons such as Long Range Acoustic Devices (LRAD or “sound cannon”), instead of bullets, fire sound waves, emitting extremely loud noises. Regular sound waves weaken the farther the people stand from the emission point. However, the acoustic signals from the sound cannon can be heard loudly up to a kilometre. That is because the sound waves are fired at a high-pressure rate. With extremely loud noises, such as those from sonic weapons, the sound waves hit the eardrum at high pressure and can cause significant damage. More important is the psychological damage that can also occur due to the “invisible attack”.
Legitimacy over the use of sonic weapons in Serbia
‘Acoustic weapons’ are not authoritatively defined or regulated in international law, nor are they the subject of dedicated multilateral policy discussions. The potential to use acoustic devices to communicate or warn, as well as to compel, intimidate, or injure, for domestic law enforcement has sparked debate in legal quarters about how such devices, in particular the LRAD, should be properly categorized.
The Serbian Law on Police does not provide for the use of any kind of sonic or acoustic weapons. Hence, controversies sparked due to the fact that firstly, the Minister of Interior gave a statement that the Ministry of Interior does not possess a sonic cannon or any other similar weapons, and afterwards he confirmed for the media that the police possess sonic weapons or colloquially called “sound cannons”, i.e., that these systems, which were purchased in 2021, are owned by the Ministry of Interior, but that they were never used because they are considered illegal weapons according to Serbian legislation.
Following the demonstrations, in April 2025, the Council of Europe Commissioner for Human Rights, Michael O’Flaherty, conducted a mission to Serbia focusing on policing of demonstrations and the working environment for civil society and human rights defenders. He observed that it is critical to ensure that the framework for democratic policing is maintained in order to ensure the safety of all citizens and that the authorities should avoid stigmatizing demonstrators through discourse that mischaracterizes demonstrations as a “color revolution”. Moreover, the Commissioner expressed concern about the unfavorable working environment for NGOs and human rights defenders, which has been further negatively affected by the reported recent action by the authorities such as the alleged use of spyware on human rights defenders and journalists, “foreign agent” type smear campaigns and the leaking of personal data in the media, including information from the files obtained during search operations by the police at several NGO premises in relation to investigations into the use of USAID funds. During his visit, he also met with Gina Romero, the United Nations Special Rapporteur on the Rights to Freedom of Peaceful Assembly and of Association.
Hence, the debate over the possible use of sonic weapons on the protests held on 15 March 2025 continues, while the prosecution opened an investigation, and the Serbian activists delivered a petition with more than half a million signatures to the United Nations in Belgrade demanding an international investigation into the alleged use of sonic weapons. Meanwhile, the Ministry of Interior, Security and Information Agency (BIA), the police, the president of the State and the president of the Government denied the use of such weapons. Consequently, the Serbian authorities requested assistance from the U.S. FBI and Russia’s FSB security service.
The Serbian Security and Information Agency published the report prepared by the Russian FSB. The report was prepared based on the: (1) study of the technical characteristics of the acoustic (sound) emitters LRAD 100X MAG-HS and LRAD 450XL, which are owned by Serbian police authorities and which opposition have stated were used by official authorities to influence civilians participating in the protest; (2) analysis of video material provided by the BIA (Security Information Agency) from the site of the “alleged” use of the acoustic weapon and the movements of persons participating in the protest; and (3) implementation of operational measures by the BIA regarding the interrogation of BIA members, police and medical teams who attended the protest. Hence, the report concludes that acoustic devices to disperse the protest participants were not used and that there are public indications of a staged provocation with the participation of a specially prepared group of people and the use of smartphones to synchronize movements while imitating the effect of an acoustic cannon and also blocking emergency services. Experts discuss that the report lacks formal requirements that a document of this kind should contain with respect to the name of the institution or expert that prepared it, the methodological structure, solid arguments, facts, and evidence from all relevant factors.
Meanwhile, the investigation, which must be independent and impartial, should provide the much-needed answers about the possible use of acoustic weapons. At the same time, if the applicants submit an application before the ECtHR, the Court will rule if there was a violation of the Convention’s rights and if Serbia failed to provide not only adequate protection of the people present on the demonstrations, but also violated their human rights by using acoustic weapons, which according to the Serbian legislation, are considered illegal weapons. This would possibly mean that the state has failed to comply with the positive obligations, especially under Article 3 ECHR of the Convention, which comprise; firstly, an obligation to put in place a legislative and regulatory framework of protection; secondly, in certain well-defined circumstances, an obligation to take operational measures to protect specific individuals against a risk of treatment contrary to that provision; and thirdly, an obligation to carry out an effective investigation into arguable claims of infliction of such treatment.
In conclusion, this case will be the first in the Court’s jurisprudence prior to the decision for granting interim measure about the use of sonic weapons. Undoubtedly, it will trace the path for the use of these kinds of acoustic weapons throughout Europe and how states should comply with their positive obligations under the Convention.