Nash said the fog-cannons were a significant deterrence to aggravated robberies, because they create a "no-go area" for offenders.
"They are unable to see anything inside the shop and it also allows employees to retreat to a safe place away from the risk of attack,
"Only Monday this week a chap went into a dairy up North with a machete, the owner set off the fog cannon – he hightailed it, no one was hurt, and nothing was damaged at all."
Porirua dairy owners Mr and Mrs Patel said the installation of the cannon was good for them.
Mrs Patel said she often worked by herself at the dairy and the cannon made her feel safe.
Police Minister Stuart Nash with Mrs and Mr Patel outside their superette. Photo / Emme McKay
The first fog cannons were installed in late 2017 and Nash said there had been a reduction in aggravated robberies, financial loss and injuries to shop workers since then.
"Since April 2017 the number of commercial aggravated robberies has fallen by 40 per cent. Serious injuries have fallen by 41 per cent and more than 1100 offenders have been caught."
He said the cannons had been activated by workers in 16 businesses and in all cases there were no injuries to staff and minimal property loss.
Nash said there were plans to install a further 33 this year and they were looking at ways to roll the scheme out to more businesses next year.
Under the scheme, businesses pay no more than $250 for the fog cannons that cost about $4000.
The initiative has cost Government $2.2 million overall.
