Police are investigating a threat made at Coronado Middle School.
An anonymous written threat against a staff member was discovered on Wednesday morning at the school, according to Coronado Police Department.
Officials said the school is safe while they perform an open investigation.
Principal Jay Maquard emailed parents at the school, calling the threat "sad and disturbing."
Earlier this month, a 12-year-old Poway student at Twin Peaks Middle School emailed a threatening message to a school administrator saying he planned to shoot a teacher and 23 students. He was detained and his parents later apologized for his actions.
A student at Pershing Middle School made a threat earlier this week targeting "popular kids" and was removed from school earlier this week.