Phoenix police are investigating after several fights at Cesar Chavez High School.
A spokesperson for the Phoenix Union High School District says the school campus was put under a shelter in place order until the end of the school day after a series of fights.
The district said officers searching cars in the school's parking lot was unrelated to the incident which led to the shelter order.
Video from Air15 showed students outside and walking around the school groups, with cars leaving the school's parking lot.
All students were released as of 3:45 p.m., the district said.
No other information was immediately available.