Brookfield School students and staff had to evacuate yesterday after another bomb threat - the second in two days.
Principal Robert Hyndman said the second phone call came to the school reception about 12.28pm, a couple of minutes earlier than the day before.
On Wednesday the caller claimed a bomb had been planted at the school and there was not much time to evacuate.
Mr Hyndman said the first caller also mentioned flying shrapnel.
"Yesterday's call was much the same as the robotic computerised call we received on Wednesday."
Mr Hyndman said staff and students were again evacuated immediately and police called.
Police arrived but there was a much reduced presence, and they did a walk through of the school and once again found no bomb, he said.
Mr Hyndman said after 35 minutes the all-clear was given.
"It is quite frustrating and highly inconvenient for everyone, but you have to treat these threats seriously," he said.
Brookfield School was one of six schools to have received bomb threats on Wednesday, and were are among 27 schools around the country who received similar threats yesterday.
Police say they are undertaking a number of lines of inquiry to establish the exact origin of these calls, and initial enquiries indicate the calls originated from overseas.