The lockdown has been lifted at Denver Public Schools' Montbello campus.
The school district said the lockdown was issued for precautionary reasons, but they did not release any other details.
The lockdown lasted just a few minutes.
The Montbello campus is located on Crown Boulevard and 51st Avenue.
This is the second lockdown at the Montbello campus this year. In January, police received reports of possible weapons on campus at 1:27 p.m., according to DPS spokesperson Will Jones. Several Denver Police vehicles were dispatched to the high school. The scene was given the all-clear an hour later, at 2:32 p.m.