Police said a student went to the school office in Pomona Elementary School in Costa Mesa complaining of dizziness, nausea and difficulty breathing, and several other children subsequently went to the office with the same complaints, the Orange County Register reported Wednesday.
Police said they discovered all the children had eaten a brownie the 10-year-old boy had given them on a campus field.
After one student asked the boy why the brownie tasted differently, the boy said, "Oh, it's a brownie that has marijuana in it," Costa Mesa Fire Department Deputy Chief Fred Seguin said.
Six boys and one girl, ranging in age from 10 to 12 years, were taken to a hospital for evaluation, officials said.
The newspaper did not report on whether any disciplinary action was being taken against the boy who brought the brownies to school.