Authorities have arrested a Southern Lehigh High School student believed to be responsible for making threats against the school.

Students were evacuated to DeSales University Wednesday and later dismissed early because of a threatening letter that was given to high school staff.

In a news release, District Attorney Jim Martin said the suspect is a juvenile and will not be identified.

The release said there is “no known threat to the community, the school district, the high school, or its students and staff.”

Upper Saucon Police investigated the threat, and swept the building using canine units. They reportedly detected no threats.

Martin thanked the administration of the Southern Lehigh School District for their cooperation in this investigation and commended members of the Upper Saucon Police Department and members of the David M. Petzold Digital Forensics Lab of Lehigh County at DeSales University for their assistance with the investigation.