In Colorado, Boulder High School was put under lockdown today (Thursday).
The move comes amid unconfirmed reports that two men in camouflage and ski masks were inside the building.
A school official said law enforcement officers were searching the building, and officers blocked off nearby streets, the parking lot and the building.
The official said a food service worker reported seeing the suspicious men.
A school district official says classes have been delayed.
Update, 10:35 am:
Classes at Boulder High School in Colorado have been canceled to give law enforcement officials a chance to search the building and its grounds. The high school was locked down this morning after a cafeteria worker reported seeing two men in camouflage and ski masks enter the building more than an hourbefore the start of classes. Police say it could just be a prank.Story courtesy of the Associated Press. (2007). All rights reserved.