Campaigners advise survivors on how to opt out of government drill on Sept 7

It will mark the second test of the national emergency alert system – after the first in 2023

Campaigners advise survivors on how to opt out of government drill on Sept 7

Mobile phones connected to 4G and 5G networks will vibrate and emit a siren sound for up to 10 seconds

At around 3pm on Sunday, 7 September, all 4G and 5G mobile phones in the UK will blare a 10-second siren blast and display a test alert from the Government.