Le Sommet Secondary School in Quebec City, Jan 17, 2013. (STEVENS LEBLANC/QMI Agency)

QUEBEC CITY — Three teenagers spent a night in jail for allegedly plotting to kill classmates and school board officials.

Police interrogated two boys, ages 14 and 15, as well as a 16-year-old girl on Wednesday. All are students at Le Sommet high school in the provincial capital.

The suspects were scheduled to appear in youth court on Thursday.

"The charge could be conspiracy to commit murder," police spokeswoman Catherine Viel said.

Electronic devices were seized and the students' lockers were searched. No weapons had been found as of Thursday morning.

A school official alerted police to Facebook postings and several police cruisers were seen at the school Wednesday.

In a statement on its website, the school said the situation is "serious" and that students who spot Facebook threats should alert authorities immediately.

Police interviewed students and parents as part of their investigation.