Investigators say THC has been found in a food sample taken from an Atlanta-area middle school where students were sent to the hospital on Valentine's Day.

The Georgia Bureau of Investigation said in a news release Thursday that tests showed THC, the main psychoactive component in marijuana, was found in one of the samples that "has the appearance of cereal."

Fulton County school officials have said 28 students at Sandtown Middle School in South Fulton were sickened and taken to hospitals. A school system spokeswoman said at the time that the students reported feeling shortness of breath and other reactions after eating food or candy.

The GBI says its crime lab received 46 food samples for testing and is continuing to analyze all items related to the incident.