At least 10 schools in New South Wales and Victoria have been placed in lockdown or evacuated their students after a series of threats were made on Friday.
An automated threatening phone message was received around 11am by NSW schools including Mona Vale Public School, Woolooware High School, St Monica's Primary School Richmond and Penrith High School.
"Police are aware of numerous threats made to schools in the Metropolitan and Southern Regions," NSW Police announced after midday.
"Investigations are continuing, and police are liasing with the Department of Education."
Victorian schools were also evacuated or placed in lock down including Berwick Lodge Primary School, Berwick Chase Primary School, Aitken Creek Primary School, Resevoir High School and Cowes Primary School on Phillip Island were evacuated.
"We're aware that a number of Victorian schools have received a threatening phone call today. They're being evacuated as a precaution," Victorian police posted to Twitter.
"We are aware that schools in a number of other states and countries have received similar phone calls in the past 24 hours."