Students in North Saanich were locked inside their school Tuesday morning following an anonymous threat, the school says.

Parkland Secondary School was placed under hold and secure status, meaning all the doors to the buildings are locked.

The school received a non-specific threat before classes began just before 8 a.m., its website says.

The hold and secure was lifted before noon and students were released from their classrooms.

Police are investigating the source of the threat.