Port Macquarie police have confirmed that the "big bang" heard throughout Lighthouse Beach on Saturday evening, December 3, was the detonation of a navy flare marker found earlier that morning.
Julia Thompson took the above photo of the smoke from the detonation blowing north-east.
The device was detonated without incident by Australian Defence Force (ADF) personnel who had been despatched from Sydney after the cylinder was discovered by dog walkers around 8.45am.
The ADF arrived at the beach around 5pm and detonated the device a short time later.
The explosion could be heard and felt around the Lighthouse Beach area.
The marker was discovered in dunes above the high tide mark about 2.5 kilometres south of the Tacking Point Surf Club.
The area was cordoned off amid fears the device was an unexploded bomb that had washed ashore.
Mid North Coast Police District Chief Inspector Mick Aldridge said police and NSW Fire and Rescue attended the location and found a grey device with a number of markings in the dunes above the high tide mark.
On it was writing that said "do not handle", "contact police" and "marine marker".
It was about 80cms long and 10cms in diameter.
While lifeguards used social media to urge the public to stay away, police consulted the Rescue and Bomb Disposal Unit, Marine Area Command and the Australian Defence Force (ADF).
The ADF advised it was likely a naval flare marker and posed no immediate risk to members of the public.
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