Staff members at Ann A. Mullen Middle School in Sicklerville noticed a strong gas odor after arriving around 7:00 a.m. and called police and firefighters.
First responders determined the odor was coming from the school's boiler room and called the South Jersey Gas Company.
Students arriving for school were kept on their buses and taken to nearby Timber Creek High School, where they stayed with their teachers, school administrators and GTPD School Resource Officers in the school auditorium.
Utility crews were able to find the source of the leak and correct the problem. Police say the building was deemed safe to re-enter at 8:43 a.m.
Students, teachers and staff were bused back to the school and normal operations resumed by 9:40 a.m.
No injuries were reported in the incident.