Tucson police have arrested a 10-year-old boy who allegedly put pills in a carton of juice and tried to get two classmates to drink it.

The boy was in the custody of a guardian and is charged as a juvenile with one felony count of poisoning food, drink or medicine, Tucson police Sgt. Mark Robinson said Thursday.

He said it's unclear what the student's motive was in bringing the pills to school and trying to get other students to ingest them.

"It could have been extremely serious," Robinson said. "I think the school administration took quick action on it and limited the other kids' exposure to this attempt to pass around tainted juice."

He said the La Paloma Academy student put various pills in pineapple-orange juice Wednesday morning and offered it to a 12-year-old boy, who was warned there were drugs in the drink by another student.

The 10-year-old then offered the drink to a girl of the same age, who also was warned about the tainted juice and didn't drink it, Robinson said.

A call to school Principal Jackie Trujillo-Watins was not immediately returned Thursday.

Six types of pills were found in the juice, in the school yard and in a trash can, Robinson said. It's unclear how many of them were in the juice.

Robinson said two of the pills were prescription medications that, if taken by somebody other than the patient they were prescribed to, lowers the blood pressure and decreases the heart rate to a potentially dangerous level.

While he said those effects could be more harmful for a child, he said there's no indication they would be life-threatening.

Robinson said the possible effects of a third prescription medication were unknown, as were the effects of the fourth type of pill — likely over-the-counter pain medication — and the other two types of pills, which were purple and yellow tablets.