According to the Sydney Morning Herald, the alarm was activated during maintenance works in the terminal.
It is reported that two flights were held on the tarmac while the incident was investigated.
T1 International and Domestic have been evacuated. Emergency Services are onsite investigating. Updates to follow.— Perth Airport (@PerthAirport) 8 мая 2018 г.
After an emergency evacuation the Perth Airport's international and domestic terminal were reopened.
We are currently reoccupying Terminal 1. Thanks for your patience while we look after your safety.— Perth Airport (@PerthAirport) 8 мая 2018 г.