Just before 5am (Tuesday 15 October 2019), police attended Boreas Road, Hamilton North, following reports of an explosion heard in the area.
Police canvassed the area and located a damaged letterbox.
No one was injured, and no other property was damaged.
Following extensive investigations, officers attached to Newcastle City Police District executed a number of search warrants at various residences and commercial properties.
The officers allegedly seized a number of firearms, prohibited weapons and various items used to manufacture and use explosive devices.
Further inquiries led officers to a location on Macquarie Street, Belmont where a 35-year-old man and a 19-year-old woman were arrested.
They were both taken to Belmont Police Station.
The man was charged with possession of multiple firearms, replica firearm, prohibited weapons and malicious damage by explosion.
He was refused bail to appear at Newcastle Local Court tomorrow Saturday 2 November 2019.
The woman was released pending further investigations.