Four students at Council Rock High School North in Newton, Penn., believed to be under the influence of an herbal supplement, were taken to a local hospital Monday, authorities said.

School administrators said they confiscated a package of small, pink pills called "SNURF" that were apparently purchased over the Internet. Newtown police are now analyzing the pills.

At about 11:45 a.m. Monday, a resource officer at the high school — located on Swamp Road in Newtown — requested an ambulance for a 16-year-old who was under the influence of an unknown substance.

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The officer then called for additional ambulances when other students demonstrated some indication of an altered state.

School officials said all four of the 10th-grade boys were transported to St. Mary's Hospital by ambulance. One male student who was in possession of the substance gave it to the staff members.

Parents and staff were with the students Monday afternoon at the hospital.

By Monday night, three of the teens had been transferred to the Children's Hospital of Philadelphia, while one of them had been released.

School officials said in a press release that no other students are at risk but issued this warning: "From the information on the packaging, we understand that SNURF is an herbal supplement with mood altering properties. We strongly recommend that anyone in possession of these pills dispose of them immediately."

Police said their investigation has just begun, and charges may be filed based on the outcome of the investigation.

Police said they believe all procedures were followed by school officials in the incident.