ROSEMOUNT — Authorities said 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 1 and 1/2 hours after the school was placed on lockdown.

The Dakota County Sheriff’s Office said after an extensive search, authorities were unable to find the man. According to a press release,  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.