Ten NSW schools were evacuated on Wednesday morning (local time) following reports of a bomb threat.
NSW police told 7 News the threat, which reportedly came via email from an unknown source, caused "significant disruptions" to staff members and students.
Police confirmed no bomb had been located after officers undertook a widespread search.
Schools including Bomaderry High in southeastern NSW were evacuated but students have since returned to class.
"This morning Bomaderry High School was one of a number of schools that received a bomb threat," principal Ian Morris said on Facebook.
"The school followed the NSW Department of Education Evacuation Procedures with police attending the school.
"Once the police determined the school was safe the students and staff returned to lessons."
Police enquiries into the threats are ongoing.
