FSB officers have launched an investigation into the possible use of a "sonic cannon" in Serbia.

Representatives of the Russian FSB have launched an investigation into the possible use of a "sound cannon" during the protests in Belgrade on March 15. This was stated by Serbian President Aleksandar Vucic on March 29.

"They will stay here for a few days, seven or eight, and then they will come out with their position around the sound cannon so that we can dispel even more lies," the Evening News newspaper quoted Vucic as saying.

The Serbian president explained that the FSB officers would help show how those accusing the government of using a "sound cannon" mislead the population.

Durability protest: new government to be formed in Serbia amid rallies

Can the opposition enter the Cabinet of Ministers and who benefits from such actions?

On March 26, Deputy Prime Minister of Serbia Alexander Vulin said that he expects representatives of the FSB of the Russian Federation to arrive in Belgrade. Then Vulin stressed that the Federal Security Service of Russia is one of the most effective intelligence agencies in the world.

The first reports of the alleged use of a "sound cannon" in the Serbian capital appeared on March 15. Then the protesters on Milan's Kralja Street heard a noise that disturbed the demonstrators.