More than a dozen Philadelphia middle school students became ill Friday after intentionally ingesting marijuana-laced Rice Krispies treats, police said.

West Oak Lane Charter School was on lockdown for most of the day as authorities investigated what happened. They said a 12-year-old bought the edibles online and shared them with 15 seventh graders ranging in age from 11 to 13 years old.

"She brought then into the school and shared them with approximately 15 of her classmates," Philadelphia Police Captain Sekou Kinebrew told Fox 29. "They all appear to be in the seventh grade. They started to show some symptoms of illness, symptoms consistent with ingesting that type of substance."

The school called the police once officials learned of the incident, Principal Charletta Zeigler told the The Philidelphia Inquirer.

The students were examined at the school and released to their parents. School officials said the scheme to eat the snacks was planned on social media.

CLICK HERE FOR THE FOX NEWS APP

“Social media drives a lot of these kinds of situations," school CEO Debbera Peoples-Lee told KYW-TV. "Parents absolutely need to be focused and monitoring the social media sites that their children are using."

An investigation into the incident is ongoing. The student who brought the edibles could face charges.