ST. HELENS, Ore. (AP) — A northwest Oregon school district has placed its superintendent and high school principal on leave, accepted the resignation of its school board chairman and temporarily suspended classes in response to an uproar over the arrests of a teacher and former teacher on sexual assault charges.

St. Helens Police Department said in a statement that officers this week arrested a current and a retired teacher in St. Helens High School due to allegations of sexual assault on students. Police said the arrest came after a two-month investigation.

The district canceled classes and after-school events on Thursday and Friday after demonstrations at the school during which students called on St. Helens School District Superintendent Scot Stockwell, High School Principal Katy Wagner and all school board members to resign or be removed.

Wagner has since been placed on paid leave and board President Ryan Scholl resigned from his position, district officials said in a social media post Friday. Stockwell was placed on paid leave during a school board meeting Friday afternoon, according to another district social media post.

Protesting parents and students told Oregon Public Broadcasting that their anger stemmed from the appearance that school officials knew about and failed to act on the allegations against the teachers for years.

Choir teacher Eric Stearns, 46, faces seven counts of second-degree sexual assault and one count of third-degree sexual assault involving six students, according to police. Stearns pleaded not guilty to the charges in Columbia County Circuit Court on Wednesday, KATU-TV reported.

Recently retired math teacher Mark Collins, 64, pleaded not guilty Thursday to two counts of second-degree sexual assault and one count of attempted second-degree sexual assault. The charges against Collins involve three students, police said.

Attempts by The Associated Press to find contact information for Stearns and Collins on Friday were unsuccessful, and no attorneys were listed for them in jail records.

St. Helen’s acting police chief Joseph Hogue told the media on Friday that his department sued the district in October and found historical reports made by students detailing the allegations against the teachers. State law requires school districts to inform law enforcement or state officials of such reports, Hogue said.

“There were several historical reports made to the high school administration from 2019 to 2023 and this also corroborated the victim’s statements that (detectives) had previously received,” he said.

Columbia County District Attorney Joshua Pond said Friday that his office is investigating whether the district violated any laws by not forwarding the reports to law enforcement.

On Friday night, district officials said the high school would remain closed Monday while staff make what officials called necessary arrangements for a safe return to school Tuesday.

“Our goal is to ensure a safe and positive learning environment, with clear steps in place to address the concerns of our students, families and community members,” the district’s statement said.

St. Helens is a small town located about 28 miles (45 kilometers) northwest of Portland, Oregon, along the Columbia River.