Virginia Tech is on lock-down after two summer campers reported seeing a man with a gun on campus.

Police followed up on the lead and are now searching the school after 13 and 14 academic campers gave a "credible" sighting.

“We’re in a new era. Obviously this campus experienced something terrible four years ago," Campus spokesman Larry Hincker said at a press conference. "Strictly, as an abundance of caution, we are going to keep the campus under alert status.”

So far, there have been no other sightings of the gunman. The original sighting occurred around 9:30 Thursday morning.

"The juveniles were interviewed...officers confirming that there information is credible and at that point we decided to issue the alert," Flinchum said. "We have not had any further reported sightings. We have not had any reports of anyone suspicious or anyone that fits this description."

The students said the gunman was about six-feet tall, with brown hair.

Virginia Tech students and faculty got text message and E-mail alerts from the police immediately after the sighting.

"Person with a gun reported near Dietrick. Stay inside. Secure doors. Emergency personnel responding. Call 911 for help," the messages read.

In 2007, a gunman and student named Seung-Hui Cho shot and killed 32 students and faculty, along with himself.