Depaoli Middle School in Reno was temporarily placed on a precautionary code yellow lockdown Friday morning.
The lockdown was announced just before 10 a.m., and was lifted less than 30 minutes later.
A message to parents from the school's principal says it was called due to someone being on campus who was not permitted to be.
The principal also said that the day continued as normal through the lockdown and everyone is safe.
