Criminals are turning their attention to the Easter break, when many people are away on holiday and increase their spending.
Cash Connect Management Solutions yesterday released its latest cash-crime trend figures, warning that business crime will spike this month because of the increase in cash at shops.
"The retail sector suffered a 150%-plus increase in robberies in 2016, and the use of plastic explosives in attempts to steal from cash-deposit devices increased by over 400%," said Cash Connect CEO Richard Phillips.
"Gangs that attack retail outlets and cash-in-transit vehicles are very sophisticated and organised," he said.
"In 90% of attacks on businesses, some form of inside information is involved, whether voluntary or unintentional.
"Criminals know what's going on, they are not simply taking a chance.''
Most attacks on shops occur when they are closed - 80% of them are on Saturdays and Sundays, between 11pm and 2am.
Syndicates usually attack in groups of six to 12 armed men.
In 2015-2016 there were close to 20,000 attacks on businesses. Cash-in-transit robberies were up by 15%, according to national crime statistics.