A teenager has been accused of making a hoax threat which forced the evacuation of a high school in Canberra's south on Wednesday, as another ACT primary school was evacuated.
Staff and students evacuated Calwell High School after a threatening phone call was allegedly received about 1pm on Wednesday.
Students at Curtin Primary School and Canberra High School had earlier been evacuated after receiving similar threats.
The teenager will appear before ACT Children's Court at a later date, an ACT Policing spokeswoman said.
News of his arrest came as police attended another Canberra school after another threatening phone call was made.
Richardson Public School was the target of another threat on Thursday afternoon, the ACT Education directorate announced via Twitter.
Students were briefly evacuated while police did a sweep of the school but returned to class less than half an hour later.
Police said investigations are continuing into the other threats levelled against ACT schools, although they are understood to be part of an international hoax.
Detective Acting Station Sergeant Marcus Boorman said every effort will be made to identify those responsible and this arrest should serve as a warning to other hoaxers.
He said police intent to prosecute these matters with "full vigour".
"There is nothing funny about a threatening phone call that causes unnecessary distress, fear and use of valuable police resources," he said.
Anyone with information should contact Crime Stoppers on 1800 333 000, or via act.crimestoppers.com.au.