Ventura County sheriff's deputies are searching for a suspect who shot at a juvenile courthouse window. No one has been injured.

Sgt. David Murray says the Superior Court Juvenile Courthouse, Juvenile Justice Center and nearby Rio Mesa High School are on lockdown as 30 deputies and a helicopter scour the area north of Oxnard.

The sheriff's office received reports of shots fired from outside the courthouse just after 9 a.m. Monday. Four shots were fired, one of them striking a window.

It was not clear how many people were in the building at the time, but Murray says about 30 people were in the courthouse's lobby area.