Ten Los Angeles students appear to have overdosed on cannabis edibles Thursday at their middle school in the San Fernando Valley, officials said.

The students, between 13 and 14 years old, were in mild to moderate distress at Van Nuys Middle School around 10:30 a.m., according to the Los Angeles Fire Department. At least six were taken to hospitals.

LAFD Capt. Erik Scott say the overdoses were possibly from edible cannabis products and investigators are trying to determine whether all 10 students got the substances from the same source.

He said firefighters searched the campus to make sure there were no other ill students.

Crews were able to determine that the substance was not related to fentanyl, a highly addictive and potentially lethal drug, and paramedics did not administer the opioid overdose-reversing drug naloxone, officials said.

No other information was immediately available, and the Los Angeles Unified School District did not immediately return a request for comment.