Duluth East High School was in lockdown for nearly an hour on Tuesday as police investigated a threat.
"When threats, whether vague or specific, are made they are fully investigated and we quickly prepare to address any safety needs that may arise," the release said.
The school went into lockdown and police responded with a search dog that went through the building. The Duluth Fire Department also responded to be there to offer support if needed.
The lockdown was listed at 2:55 p.m. when police gave the school the all clear. Teachers offered some time to debrief as needed, with the district noting: "Even vague threats are stressful to all involved and we know they can have a significant impact on our entire school community."
Counselors and social workers are available to offer support to students and police will remain at the school until the end of the day to help people "feel secure."
Students, staff and the school are all safe, the release said.