MONTREAL -- A Montreal North high school was locked down on Thursday after students told administrators a man pulled a gun on them, a spokesperson for the school board said.

A group of students from the school, Lester B. Pearson High School, had gone to a restaurant during their lunch hour and had an altercation with a man there, according to English Montreal School Board spokesperson Mike Cohen.

The students ran away when the man pulled out a gun and threatened them, they told school administrators, prompting a school lockdown. No one was injured, Cohen said.

No one was allowed to leave the building during the afternoon while it was under lockdown, Cohen said.

Police received a call from the school around noon, a spokesperson for the Montreal police said. Officer arrived and investigated, but have not identified a suspect.

No specific threat was made against the school, the police spokesperson added.