An increased police presence has been added at the University of Michigan after a possible threat of violence was found written on a campus bathroom wall.
The school's Division of Public Safety and Security announced Thursday that graffiti including the message "School Shooting 4/13" was found in a campus building.
Police say it doesn't appear that the threat that included Friday's date is credible.
Still, officials boosted the police presence at the Ann Arbor campus.
Police says the graffiti has been removed from the bathroom and local, state and federal law enforcement were notified.
University police say the campus was fully operational Friday. An investigation is ongoing.