SINGAPORE – The islandwide network of Public Warning System sirens will sound a minute-long “important message” signal on Sunday (Sept 15), the Singapore Civil Defence Force (SCDF) said on Friday.

The SCDF advised the public not to be alarmed by the sirens, which are expected to go off at 6.20pm.

The “important message” signal will also sound on all smartphones that have the SGSecure mobile app installed, if they are not put on silent or vibration mode. The signal on these devices will stop once the message is acknowledged or after 20 seconds.

The public can tune in to any local radio station or free-to-air Mediacorp television channel for a brief message when they hear the signal.

Those who miss the message may visit the SCDF’s website at for more information.

The annual exercise is part of the SCDF’s efforts to familiarise the public with the Public Warning System and raise awareness on how the public should react to the sirens.