WA Police have confirmed a homemade bomb was thrown at the stage at the start of Boorloo/Perth's January 26 Survival/Invasion Day protest.
On Monday evening WA Police Commissioner Col Blanch told media a device the size of a coffee cup had been thrown towards the stage from above. Forrest Place is bordered on one side by a high, wide balcony/mezzanine.
"A device that was located just in front of the stage contained ball bearings, contained screws, and those items were wrapped around an unknown - at this stage - liquid in a glass container," he said.
Earlier in the day move on orders were issued, and police began using megaphones to tell the crowd of over 2000 people to disperse around 1pm, warning "there is something in the crowd that poses a risk your safety".
Shortly thereafter WA Police said in a statement they were "responding to reports of a threat in Forrest Place in Perth CBD".
"Significant police resources have been deployed to the area, and an exclusion zone has been established," they said.
"Members of the public are asked to stay away from the area and await further advice.
"One person is in custody and assisting police with inquiries. We will provide more information as soon as possible."
