For the second day in a row, smoke disrupted classes at Memorial High School in Sydney Mines.
Regional Police spokesperson Desiree Vassallo tells The Coast police were called this morning about a smoke flare in the school.
Vassalo adds police went to the school and found nothing during their search.
She says there were no injuries and it seems to be another prank.
A threat caused an evacuation yesterday after it was called in between 1-1:30.
Regional Police searched the building and found no bomb.
They later called the threat a hoax and nobody was hurt.
The school was evacuated last Thursday after a smoke signal canister was set off inside the building.