Threatening graffiti forced officials at Farleigh Dickinson University to close their Florham Park campus to all non-essential personnel Friday.

Security on the campus was beefed up after administrators found a message in a residence hall that stated ?FDU is next.? The message was spray painted in the stairwell in Hamilton Twombly Residence Hall. Security guards were posted at every entrance to check cars coming onto campus.

University officials say they also found an overturned trash container with a number of handwritten sheets with the same message.

The school e-mailed students informing them about the increased security.

?The university will increase the presence of public safety officers around the campus. Guard booths are manned at night and other on-going safety measures that are an integral part of the campus safety program are in effect.?

The threatening notes are now in the Morris County Sheriff?s Department crime lab.