Threatening phone calls that sparked the evacuation of 10 Queensland schools don't appear to be credible but will be fully investigated, police say.
Queensland Police are confident the calls originated overseas and have been designed to cause significant disruption and media coverage.
"At this time, there is no credible evidence the threats could be carried out here," police said in a statement on Tuesday.
"Investigations into the threatening phone calls are continuing, but at this time there is no cause for alarm."
Police and Queensland's Department of Education and Training haven't said which schools received the calls.
However, media outlets have named the schools as The Gap State High School, Bounty Boulevard State School, Surfers Paradise State School, Oxenford State School, Caningeraba State School, MacGregor State High School, Buddina State School, Townsville State High School, Woree State High School and Glenmore State High School.
Bounty Boulevard State School principal Paul McSwiney took to Facebook to reassure parents after his school was evacuated.
"There has been a hoax phone call this morning which has resulted in us having to evacuate the school to the oval," he posted on the school P&C's Facebook page.
"All students are safe and are resuming learning. There is no necessity to contact the school."
Four plain-clothes detectives were seen leaving The Gap State High School, while the bomb squad searched Townsville State High school for "suspect devices".
Queensland police commissioner Ian Stewart has briefed Premier Annastacia Palaszczuk on the threats.
Schools in NSW, Victoria, Tasmania, and the ACT were also evacuated in the latest round of threatening calls on Tuesday.
