Three 15-year-olds will appear in the Nelson Youth Court today after members of the public interrupted a dairy robbery in the city.
Police said three males entered the dairy on Roto Street, Tahunanui, armed with knives, about 3pm yesterday.
Two people saw what was going on and helped the dairy's owner overpower a teenager.
Police arrested two teenagers shortly afterwards and detained a third later in the evening.
They said they did not recommend confronting armed offenders, but the pair's actions did result in an early arrest.
All three will face charges of aggravated robbery.