The incident brought a heavy police presence to the campus after more than a dozen students were exposed to the drug.
Remnants of the white powder the Tulare County Sheriff's Office confirms is cocaine can be seen at the bottom of two Ziploc bags.
Those bags stored two separate balloons that were found on the playground by students at Carl F. Smith middle school in Terra Bella.
#BREAKING: These are the balloons found on a playground @ Carl F. Middle School in #TerraBella. @TulareSheriff says cocaine was found inside of them. 13 students were exposed, 2 were taken to the hospital. Officials say 1 student has been linked to the incident. More at 6 @ABC30 pic.twitter.com/XZOdjUeQSX— Cory James (@CoryABC30) September 14, 2018
"They were messing with the balloons and pulled open the balloons and saw the white powdery substance," said Tulare County Sherriff's Office Sheriff Mike Boudreaux.
The disturbing discovery happened just before 9 a.m. on Friday, sending panic across the campus.
"Two of the students became very dizzy -- not disoriented, but very dizzy," said Boudreaux.
Authorities say 13 students are believed to be exposed to the drug.
All of them examined by paramedics and had negative results. But two children were taken to a local hospital to be evaluated as a precaution.
Parent Vincente Morales has a seventh-grader at the school.
He was caught off guard by the news and plans to speak with administrators.
"I want to see what happened. I want to talk to the principal," said Morales.
Investigators say a 13-year-old boy reportedly brought the drug-filled balloons to school. Officials believe he got them from his home, which is where a search warrant was later served.
The school district released a statement saying, in part: "We will take this incident as a learning opportunity to reaffirm our position as a drug-free school and remain vigilant."
At this time, it is unclear if he the student accused of bringing the cocaine to school will face any sort of disciplinary action.