School officials in northern Colorado are asking parents to take care with their newly legal recreational marijuana, after fourth graders were caught dealing the drug on an elementary school campus.

John Gates, director of safety for Weld County School District 6, said Wednesday that the students involved, three 10-year-old boys and a 10-year-old girl at Greeley's Monfort Elementary School, faced tough discipline but not suspension or expulsion. He would not elaborate on their punishment.

Only one student admitted to trying any of the drug, a small bite of an edible marijuana item, and a subsequent medical exam did not indicate any harmful effect had been caused, Gates said.

The marijuana appears to have been legally purchased by adults — grandparents in two families — and no charges were expected to be filed, Gates said. He said the parents of the students were concerned and working with the school on discipline.