MODESTO, Calif. -- Four students at Modesto's Beyer High School were arrested Monday on suspicion of selling Vicodin, marijuana and other drugs on campus, police said in announcing the results of an undercover sting operation.

Police Sgt. Brian Findlen said an undercover officer enrolled as a student and purchased illegal drugs from the students.

Findlen said the students also sold police other prescription medication and a hallucinogen billed as Ecstasy. Some of the sales took place during school hours.

Some of the students were removed from their classrooms by police at 8:30 a.m. and were booked into the Stanislaus County Juvenile Detention Center.

"The Modesto Police Department is committed to keeping our schools safe and will conduct operations to arrest those responsible for distributing drugs on campus," Modesto Police Chief Roy Wasden said in a prepared statement. "We will continue to work closely with Modesto City Schools to ensure that those who are drug-involved are brought to justice and given the help that they need."

The names of the arrested youths were not released because they are minors, but police said all four suspects are 17-year-old boys.

Police said the boys face the following charges:

The first suspect is accused of selling a substance falsely represented as a controlled substance and sale of a controlled substance. He was also allegedly in possession of marijuana at the time of arrest.

The second suspect is accused of selling marijuana.

The third suspect is accused of selling a controlled substance.

The fourth suspect is also accused of selling a substance represented as a controlled substance. He was taken into custody at his home after he failed to report to school.

More arrests are expected as the investigation continues, Findlen added.

Findlen said police worked with the Modesto City School District after receiving reports of drug sales in the school.