MEMBERS of the NSW Police Bomb Squad this afternoon safely detonated an 'extremely volatile' homemade explosive discovered inside a freezer in Coffs Harbour.

A house was cordoned off in Griffith Ave this morning by police before specialist officers travelled to the Coffs Harbour home and removed the unstable chemical compound.

Police said it is understood a youth may have tried to make home-made fireworks or explosives.

After the substance was discovered, a family member reported the incident to police on Wednesday.

The chemicals were found inside a freezer outside the home.

The occupants were evacuated and the home was cordoned off for safety.

Police said it is understood several chemicals were combined to crystallize acetone peroxide.

It's thought directions to make the explosive compound were sourced off the internet.

Online videos show how volatile the substance can be when it explodes under heat and friction. 

Police say under no circumstance should anyone attempt to make the dangerous compound.

Acetone peroxide has killed and injured and has even been used by terrorism groups in crude IEDS (Improvised Explosive Devices) because of its instability.

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