More than 90 percent of people should hear their mobile phones blast a warning tonight, as the nation-wide test of the Emergency Mobile Alert System takes place.

The test checks alert systems, cell towers and whether phones can receive an alert.

People have begun reporting receiving the alert shortly after 6.15pm.

Minister for Emergency Management Kieran McAnulty said it was a tool that can alert people when their life, health, or property was in danger.

He said when the alert sounds, people should stop and read the message and take it seriously.

Tonight's test is the fifth annual test and is scheduled to happen between 6pm - 7pm.