Armed police swarmed a street in North East Valley this afternoon after a man was seen brandishing an object that looked "like a firearm".
A police spokesman said they were called to Crown St about 3.15pm today after reports of a man with what appeared to be a firearm.
Police arrived, armed as a precaution, and located the man.
He was taken into custody and was assisting police with their inquiries, the spokesman said.
No firearm was found to have been involved in the incident, but police did find a knife at the scene.
The resident, who wished to not be named, said watching the arrest was "crazy".
"We just saw it, someone was running, police were just everywhere and the owner of the car being searched is now sitting in the back of that police car . . . it was all very quick.
"They just showed up, stood around the corner with guns and the man who got arrested was just driving down the road.
"They popped out, got him out of the car and it was all over, next thing the man was on the ground being arrested," he said.