A bullet has been fired into the window of Macquarie Fields Public School in Sydney's southwest.
No students or teachers were injured in the incident, which occurred about 12.45pm on Tuesday, NSW Police said.
Police were called to the school and determined the bullet, which broke a window, came from a small calibre weapon.
A crime scene was established and the bullet was seized for forensic examination.
The school was not placed into lockdown at the time of the incident, police said.