ALGONA — Algona schools were closed Friday after the district received a threat of an explosive device in one of its buildings.

According to school officials, they received an automated message early Friday morning claiming that a bomb had been placed inside the high school.

“The facility was searched and cleared by local officers and the department’s explosive detecting dog … who is trained specifically for this type of situation,” Algona Police said in a news release.

Authorities said the building was “clear” but said the building would remain closed Friday. Evening and weekend activities will continue as normal.

“We have been working with the Kossuth County Sheriff’s Department and the Algona Police Department to ensure the safety of our buildings by following our regular safety protocols,” said Superintendent Joe Carter in a published statement online Friday morning. “We have learned through working with state and federal authorities that this is a threat that has been made in other places throughout the nation.”

Algona Community School District wasn’t the only one in Iowa to receive the automated threat. Officials at AGWSR and Alburnett also confirmed similar threats, none of which were legitimate.

“The voicemail was a computer-generated voice, and the origin of the call is unknown,” the Linn County Sheriff’s Office said in a news release.

The Iowa State Fire Marshal as well as multiple county sheriff’s offices are currently investigating the incidents.