Northridge Academy High School was briefly placed on lockdown Tuesday morning while police investigated a report of an unattended package.
Los Angeles School Police said the lockdown was a precaution around 9:20 a.m.
Students and faculty at the school, in the 9600 block of Zelzah Avenue, were evacuated to the school's field while police and K-9 units conduct a search of the classrooms.
The lockdown was lifted about 10:20 a.m. and LASPD Chief Steven Zipperman tweeted that no suspicious package or device was found.
Normal school operations are expected to resume for the rest of the day.