Cape Breton Regional Police are investigating separate threats at three high schools within 24 hours.

Memorial High School in Sydney Mines was evacuated Wednesday morning after a staff member found a note of a threatening nature.

After spending two hours outside in freezing temperatures, classes were cancelled and students were sent home for the day.

Police searched the school and said they found no evidence of a threat. They are now investigating the source of the alleged threat.

Police also responded to Glace Bay High School after receiving a report about a potential threat involving a vehicle. They say someone made an anonymous call to the school, threatening that a vehicle with a weapon was headed for the school.

Officers contained the area and blocked all entrances to the school. The school was placed on hold-and-secure while police searched the area.

“It’s putting me through a lot, especially when I’m talking to her on the phone, she’s crying, she’s scared and, you know, I’m scared,” says Natasha O’Handley, whose niece attends Glace Bay High School.

The hold-and-secure was lifted a few hours later and classes were back to normal Wednesday afternoon.

Police remained in the area for the duration of the school day as they investigated the alleged threat.

The incidents at Memorial High School and Glace Bay High School came a day after another Cape Breton High School was on lockdown while police responded to a weapons complaint.

“I think it’s just a copycat from what happened yesterday,” says student Andrew Gillis.

Police were called to Riverview High School in Coxheath, N.S. after 10 a.m. Tuesday after a note was found, claiming there may be a weapon inside.

The school was on lockdown and access was restricted for close to five hours while officers searched the building.

After a thorough search, investigators said there was no evidence of a weapon or threat to students’ safety. The students were dismissed around 3 p.m.

“It upsets students, it upsets staff and it upsets parents,” says Cape Breton-Victoria Regional School Board spokesperson Charles Sheppard of the alleged threats. “It utilizes resources.”

Nearly 50 police officers were dispatched to the three schools within 24 hours. Police say the alleged threats are not just pranks, but are also punishable offences.

“They are criminally punishable and we will pursue each of these cases to determine who is responsible,” says Cape Breton Regional Police spokeswoman Desiree Vassallo.

With files from CTV Atlantic's Ryan MacDonald