Brief sirens and vibrating mobile devices flashing messages could be heard and seen across the Rural City of Wangaratta on Monday, as the federal government staged a test of its AusAlert emergency warning system.

However, not all devices received the test warning, which was sent as part of the test ahead of a planned launch of the system in October.

The government has reiterated information it provided in the lead-up to the national test, saying those who did not receive the test alert do not need to do anything.

Part of the reason for the test was to detect any issues, and there are many reasons why devices may not have received the practice alert, including that they:

* may be older and not support AusAlert, meaning they are not compatible;

* may not have been updated to a software version that allows emergency alerts to be received;

* might not have had a mobile signal at the time of the test;

* may have been switched off, in aeroplane mode or not connected to any mobile tower at the time of the test; or

* the closest mobile tower may not be working due to maintenance or outage, or may not have any power.

Information gleaned from the test, including feedback from the public, will be used as the system is prepared for its launch.