A 14-year-old boy has been charged over an incident involving two children who were pricked by a hidden syringe in separate incidents at a supermarket in Melbourne's north.

A 14-year-old boy from nearby Coburg has been charged with two counts of recklessly causing injury.

The boy has been granted bail and will appear in a children's court in September.

The incidents happened around the deli area of a Coles supermarket on Pascoe Vale Road, Broadmeadows on Monday and involved a needle placed under a rail.

The first child was pricked about 1:30pm and there was another incident about an hour later and the needle was discovered by the child's mother.