Geoscience Australia have confirmed a large bang that was felt right across Perth's southern suburbs was not an earthquake.
The explosion happened just before 11.30am on Wednesday with hundreds of people reporting their houses shook.
Affected suburbs include Mandurah, Secret Harbour, Rockingham, Baldivis, Kwinana and surrounding areas.
A Geoscience Australia spokesperson said their seismologists have not detected any recent earthquakes.
The investigation continues into what caused the loud explosion.