Police were called to Cambridge Court around soon after 11am today (August 8).
Armed police responded and a large cordon closed Amhurst Park and surrounding roads.
A man in his 50s was arrested on suspicion of possession of a firearm and remains in police custody.
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There were no injuries and officers say there is no threat to the public.
John Quinn was in the area when he was turned back by the police.
He said from the cordon: "They're down there with machine guns and everything.
"I was walking down the back near Hillside Road and the police turned me back.
"I didn't see anything. There were lots of people all wanting to have a look.
"I wasn't really afraid - there are people at shooting at you every day."
A Metropoli