MINNEAPOLIS (WCCO) — Rosemount Middle School officials have locked the school down after receiving a threatening call Monday morning, according to police.

At 10:09 a.m., police officers were dispatched to the school, who reported to police that the school had received an anonymous phone call from an outside number where the caller told the school that he or she had a gun and would open fire on the children.

It was then determined that the school would lock the students in the building while maintaining normal operations inside, police said.

A search of the school and school grounds turned up nothing suspicious and no suspicious individuals were located.

The case is being investigated by Rosemount police.