MORRIS, Ill. (STMW) – Bomb-sniffing dogs searched a Grundy County middle school complex after a threat was found written on a bathroom wall, the Herald-News is reporting.

Morris police Chief Brent Dite said police had to take the threat seriously but found nothing suspicious at Shabbona Middle School in Morris, about 20 miles southwest of Joliet.

District 54 Supt. Teri Shaw said graffiti saying, “I’m bringing the boom to Shabbona,” was found earlier in the week in a boys bathroom near the art room on the east side of the building.

Shaw pointed out the message could be a reference to a recently released comedy movie about a schoolteacher called “Here Comes The Boom,” but the staff could not make that assumption.

Dite said the county bomb squad and police dogs searched the middle school and adjacent Grundy County alternative school Thursday but found nothing. The search began around 5 p.m. and lasted more than five hours. Shaw said there have been no similar incidents in the district.

Parents were notified with emails and voice mails as the search was conducted and shortly after it ended. Shaw said even though no threat was found, some parents did choose to keep their students home Friday.

“We do have an increased police presence there (Friday), but there have been no incidents,” Dite said.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)