Air-raid siren
Air alarm – a signal to alert the public about the threat of an attack from the air. It is activated in the event of a risk of an airstrike or missile launch in the direction of a populated place or region.
The air alert is triggered when the Air Force of the Armed Forces of Ukraine's radar systems detect enemy aircraft's movement toward the territory of Ukraine. A siren indicates that an aircraft that can attack with bombs or missiles are approaching a particular region or that a missile has already been launched. According to the information from the radars, the missile's direction is determined, considering that it can change its course to the right, left, or even disappear from the radars. Based on these data, an air alert signal is activated in the regions along the trajectory of its flight [РБК – Україна].
When the sirens sound three times in a series with a one-minute interval between the series, this means “important message – listen to the radio.” If you hear this signal, you should seek information. Information about what is happening and what you should do will be provided through various media, such as radio, television, and social media. This signal can be used in peacetime and wartime [Sikker hverdag].
Чому звучить сирена? Як і коли спрацьовує повітряна тривога. РБК – Україна. Retrieved from: https://www.rbc.ua/ukr/news/pochemu-zvuchit-sirena-srabatyvaet-vozdushnaya-1662476062.html
Air raid sirens. Sikker hverdag. Retrieved from: https://www.sikkerhverdag.no/en/being-prepared/warning-and-information/air-raid-sirens/