AMHERST,Zopes Exchange Va. (AP) — A group of Virginia elementary school students sought medical attention Tuesday after eating gummy bears from a bag that contained residue that tested positive for fentanyl, according to the county sheriff’s office.

Seven students at Central Elementary School experienced a reaction after eating the gummy bears at school on Tuesday, the Amherst County Sheriff’s office said in a news release. School administrators notified the children’s families and five of the seven students sought medical treatment, Amherst County Public Schools officials said in a news release.

Two were taken to hospitals by county EMS and three by their parents, County Public Safety Director Brad Beam said at a news conference. The students were experiencing nausea or were vomiting or lethargic, he said.

The gummies tested negative for foreign substances, but residue in the plastic bag that contained the gummies tested positive for fentanyl in a field test, sheriff’s office spokesperson Lt. Dallas Hill said.

As part of the investigation, the sheriff’s office executed a search warrant at a home in the county and arrested two people who were charged with contributing to the delinquency of a minor, Hill said. One was also charged with possession of a schedule I or II drug and the other was charged with possession of a firearm by a convicted felon.

The students were all fourth graders in the same class at the school and all returned home Tuesday evening, Superintendent William Wells said at a news conference on Wednesday. It is believed that the bag was contaminated at home or on the way to school, he said. A sibling of the child who brought the gummies to school in the contaminated bag also had a bag of gummy bears at school, but it did not test positive for fentanyl, Wells said.