ROSEMOUNT, Minn. — Authorities say Dakota County Technical and Community College in the eastern Twin Cities was placed on lockdown after a report of a man with what appeared to be a firearm on campus.

The Rosemount campus gave the all-clear just before 3 p.m. Wednesday, about an hour and a half after the school was placed on lockdown.

The Dakota County Sheriff’s Office says after an extensive search, authorities were unable to find the man. KSTP-TV reports authorities do not believe there is any known threat to the school.

According to the sheriff’s office, the school bans firearms on its grounds.