Hundreds of students were evacuated after several primary and high schools in two states of Australia received bomb threats, police and school authorities said.
The police in south-eastern states of Victoria and New South Wales conducted separate operations and investigations into the threats that was made Friday morning.
"Police are aware of numerous threats made to schools in the Metropolitan and Southern Regions. Investigations are continuing, and police are liaising with the Department of Education," New South Wales police said in a statement.
"We're aware that a number of Victorian schools have received a threatening phone call today. They are being evacuated as a precaution," Victoria state police said in their Twitter account.
"We are aware that schools in a number of other states and countries have received similar phone calls in the past 24 hours."
It was not clear how many schools were affected, but hundreds of students were gathered in the school grounds in various districts of the two states before they were sent back home.
Rodney McKenzie, the assistant principal of Cowes Primary School on Phillip Island, said they evacuated more than 500 students after a receptionist received a threat call on their school phone.
"It was a computerised message, like a robot speaking. It said there was a bomb located in the school in a backpack," Mr McKenzie told The Age news website.
"Police have inspected the school and there's no perceived threat, but students won't be returning to school today," he said.
Schools in Australia were closed for the past month for summer break. For many of the states, Friday marked the start of the new school year.