CORNELIUS, N.C. -- Hough High School went on a lockdown on Tuesday for the fourth time in the last eight days.
Charlotte-Mecklenburg School Police tell NBC Charlotte the school briefly went into a "modified" lockdown on Tuesday morning because of a rumor of a threat.
The modified lockdown restricted movement within the campus.
CMS Police investigated the rumor and lifted the threat around 11:15 Tuesday morning after finding the threat was not warranted.
Students were not evacuated.
The modified lockdown lasted approximately 40 minutes, officials say.
In the last eight days, Hough High School has been evacuated three times due to threats of a suspicious device on the campus. Last Tuesday, students were evacuated from the building and moved to the school's football field twice as Cornelius Police, CMS Police and the Charlotte-Mecklenburg Police Department's bomb squad and HazMat team searched the building.
Then, on Monday, the students were once again moved to the football field while authorities combed the campus for a suspicious device.
On two of the three occasions, a device was found but deemed to be not dangerous.
As of now, three people have been charged in connection with the bomb hoaxes at the school.