A car was set on fire outside a mosque in Perth's south-east on Tuesday evening while hundreds of worshippers prayed inside.
The freshly sprayed words "Fuck Islam" stained a wall outside Thornlie's Australian Islamic College and mosque while the four-wheel drive burned.
"It is believed an accelerant was used to start the fire," Western Australian police said.
The Toyota Prado was completely gutted while three other vehicles suffered heat damage before firefighters managed to extinguish the flames.
Three people were seen running down an alleyway, police said.
"The lack of attention and concern would not be the same if this had been a Muslim detonating a car bomb outside the footy," Islamic community worker Mohammed El-leissy told BuzzFeed News.
These different standards were making many Muslim Australians feel "marginalised and outcast", he said.
"In the end aren't we all Australians?"
A spokesperson from the Australian Federal Police - which is responsible for investigating acts of terrorism - confirmed the matter would be dealt with by state police only.
Gina Rushton is a breaking news reporter for BuzzFeed News and is based in Sydney.
Contact Gina Rushton at firstname.lastname@example.org.
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