A male student at /*La Mesa Junior High*/ reported headaches, nausea and dizziness after buying and drinking some /*Aquafina*/ bottled water at about noon.
Other students quickly made the same complaint.
"I was feeling light-headed, I couldn't walk well, my legs were wobbly," said student Cody Commons.
At least six of the students were taken to the hospital, but are expected to be fine.
Several girls got sick sipping from the same bottle.
Student Danielle Saavedra was not hospitalized, but she said she got a headache after drinking the water.
"It tasted very funny, and I didn't like it, so I threw it away," she said. "I only got a little taste of it, and then I just like spit it out."
Pepsi, which makes Aquafina, says there's no evidence the incident was "caused by anything in our manufacturing process."
The FBI had sent a hazardous materials team after the incident, but so far, testing has revealed no contamination.
Initial tests found nothing wrong with the water, but an L.A. County Fire inspector said the bottles contained a bleach-like substance.
"The two bottles in question, I examined also. They were cloudy, as compared to a regular bottle," Fries said.
"They did have a different smell, I mean, water shouldn't have a smell," he said.
Fries said he did not know if it was bleach in the water.
The FBI was called as a matter of routine, but according to the school principal, is not participating in the investigation.
"My job is to make sure our kids are safe, and we'll do everything necessary to make that happen," Fries said.
A spokesman for Pepsi Bottling Group said in a statement, "We have examined and tested numerous bottles that were produced at the same time as those in this case and have found them to be free of any problems whatsoever."
Officials do not believe students or anyone on campus tampered with the bottles.
"Those two students were very specific that it fell out from the machine, it dropped down when they put the money in, and when they opened it, it made the cracking sound, and so, we're real concerned here," Fries said, adding that he believed the problem was something that came to the school.
Further tests are expected to be performed.
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