[Introduction]: Civil defense siren is divided into three types: pre-alert, air alert, and de-alert. Civil defense siren the sound feature of releasing the alarm is continuous ringing for 3 minutes.
Civil defense siren can be divided into three types: pre-alert, air alert, and de-alert. Among them, the sound feature of the civil defense siren release alarm is continuous ringing for 3 minutes.
Lift the alarm: The public can go out of the underground air defense shelter, civil air defense project and air raid shelter and resume normal work with a continuous sound of 3 minutes.
Lifting the alarm is a signal to report the enemy’s attack. The purpose is to enable the region and troops to resume normal work in due time. Usually, the signal of releasing the air alert is sent when the enemy’s air strike has ended or the fact has proved that the original air strike direction is wrong. The ground attack warning signal has been sent out in hours when the enemy’s attack threat has been threatened.
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