Students at St. Patrick’s high school will notice a few more police officers in the area today.

The St. Clair District Catholic School Board called Sarnia police after a threatening letter was found in the desk of a student late Monday. Officials say it was a “a generic message alluding to a threat at the school” and “Sarnia Police do not believe the threat to be credible; nor do they advise that the school be closed.”

By the morning, police had identified the student who had admitted to the prank. Board officials say they’ll be following up with the student.

Director of Education Schott Johnson, in a news release, said “As a precaution, there will be an increased police presence in the area throughout the day” Tuesday.

“Acts of mischief such as this one will be dealt with through the fullest extent of the law and the greatest measures possible under authority of the board,” he added.