Students and staff at a number of Canberra schools were evacuated on Friday morning after receiving bomb threats.
Police said the threats came via email but were believed to be linked to an overseas Bitcoin scam, after similar emails were circulated in other states and countries.
As a precaution, ACT Policing said it was treating the threat seriously.
Lyneham High, Hawker Primary School, Malkara School, Lyons & Narrabundah Early Childhood School and Charnwood-Dunlop School were all evacuated, but the education directorate said they had returned to schoolas of 12:30pm.
"ACT Policing investigated all schools this morning and they have all returned to normal operations," a directorate spokeswoman said.
"Whilst [such safety procedures are] disruptive for schools, and can cause concern for parents, the safety and wellbeing of our students and staff is of utmost importance."
Police advised any organisation receiving the threat to follow their own internal procedures.
"However at this time it is believed these emails are designed to fraudulently elicit payments," a spokeswoman said.
In a message to parents and the community on Friday morning, Lyneham High principal Rob Emanuel said police had attended the Goodwin Street campus and were investigating the threat.
Parents were advised that they did not need to pick up their children from school.