ASHEVILLE (AP) — The University of North Carolina at Asheville campus was placed on lockdown Friday after several offices received threats involving a Black Lives Matter mural.

Offices at the school received threatening emails and a demand overnight that the mural on campus be painted over, news outlets reported. The school advised faculty, staff and students to shelter in place, and employees other than essential personnel were told to stay away from campus. The school also canceled in-person classes, practices and activities on campus Friday.

UNC Asheville Chancellor Nancy J. Cable said in her announcement that she hopes to reopen the school as soon as possible, but not before this morning. Entrances to the school have been blocked.

Approximately 3,600 students are enrolled at UNC Asheville, according to the school’s website.

Campus communications manager Steve Plever declined to describe the nature of the threats.

State and local authorities are investigating.