Health officials are investigating whether a flu-like illness that sent about 20 high school students to the hospital Wednesday was linked to candy bars.

The chocolate-covered caramel bars were sold as a fundraiser at Liberty High School in Clarksburg, said Chad Bundy, administrator of the Harrison-Clarksburg Health Department. He said he did not know the brand of the candy or the company that made it.

Assistant Principal Steve Gibson said the students ate the candy Wednesday morning before classes began. School officials called police after the students became ill.

"As a precaution, at the initial onset we didn't know what it was, so they came in as a precaution," Gibson said.

Clarksburg Police Chief John Walker said about eight students in gym class came down with symptoms, such as nausea and vomiting. Later in the morning, another dozen students complained of similar symptoms, he said.

The students were taken to United Hospital Center in Clarksburg, where they were treated and released, a hospital spokeswoman said.

Most of the students are freshmen.

A call to the federal Centers for Disease Control and Prevention was not immediately returned.

Bundy said it would probably be a week before results of lab tests are known.