More than 1500 children, including some as young as 10, have been arrested for gun offences in the last three years.
Figures from police forces across the UK show a 20 percent jump in the number of cases in the last 12 months.
Cambridgeshire Police arrested seven boys on suspicion of firearm offences last year.
That compares with eight in 2014 and two in 2013.
Two 17-year-olds were charged with possession of an intimation firearm in 2015, while a 15-year-old was charged with firing an air weapon in 2014.
Nine under 18s were arrested by Northamptonshire Police on suspicon of firearms offences last year.
That’s up from six in 2014 and three in 2013.
Of two who were charged – one was 16 the other 17.