Gun Scare at Virginia Tech, Scene of 2007 Massacre

Authorities issue a lockdown on Thursday at the campus of Virginia Tech, after a man suspected of carrying a gun was seen on campus. The school was the site of a 2007 mass shooting that killed 32 people.

An alert on the school's Web site read: "Person with a gun reported near Dietrick (dining hall). Stay inside. Secure doors. Emergency personnel responding. Call 911 for help."

A subsequent crime alert said three youths attending a camp on campus reported seeing a white man who appeared to have a gun covered with a white cloth.

The crime alert reads: "Officers responded immediately to the area but found no one matching the description." 

Activity at the school grinds to a halt after the lockdown. The school is currently being used to house dozens of academic and sports camps for children over the summer vacation.

The crime alert describes the suspect as 6 feet tall with light brown hair, wearing a blue and white striped shirt, gray shorts and brown sandals. 

Virginia Tech was criticized for not reacting quickly enough when gunman Seung-Hui Cho killed 32 people on campus in April 2007. They responded quickly this time - after sending out an initial warning on the Web site, the school continued to update people on campus.

An FBI spokeswoman says they are aware of the reported incident and agents are already on the scene.