Police responded to a bomb threat at Lincoln High School, made by a student. (FILE PHOTO)

A Canterbury high school was evacuated after a student made a bomb threat.

Police were called to Lincoln High School just after 9am on Monday, a spokesman said.

A student had told staff about a "concerning conversation" with another student.

At noon, the spokesman said police had completed their search and declared it "all safe".

"Police spoke to those involved and have now left the scene," he said.

"Students are back inside now, it's all clear."

Lincoln Primary School, which shares the grounds along with Kidsfirst Kindergartens Lincoln, had not been evacuated.

"It's business as usual over here," principal Vivienne Butcher said.

"We've been kept fully informed by the staff of the high school, but it hasn't affected us."

Kidsfirst head teacher Joyce McHerron said she heard alarms activate earlier, but the kindergarten had not been informed of anything going on at the high school.

Lincoln High School principal Kathy Paterson declined to comment.