Prince Andrew High School was briefly locked down on Thursday morning after a prank call. (www.wikipedia.org)

Halifax Regional Police have launched a public mischief investigation after a report of a student with a weapon led to a brief lockdown Thursday morning at a Dartmouth high school.

Staff at Prince Andrew High School on Woodlawn Road got a call at 11 a.m. from an anonymous caller who said a student was inside the school armed with a weapon.

The school called Halifax Regional Police and initiated a lockdown.

Officers and a canine unit searched the school and did not locate the student or a weapon. It turned out the student named by the anonymous caller was at home and never had any involvement in the incident, nor was he ever armed.

The lockdown was lifted at 11:30 a.m.

"Officers are now investigating the matter as a public mischief incident," Halifax Regional Police Const. Pierre Bourdages said in a statement.

"Police take incidents of this nature very seriously as they are troubling for everyone involved and tie up police resources."

A person convicted of public mischief may be sentenced to up to five years in prison.