Three children attending a summer camp at Virginia Tech reported a gunman near the campus' main dining hall, Dietrick.

The juveniles reported seeing a man with a handgun "covered by a cloth or covering of some sort," the university said in a statement. The incident was reported at 9:09 a.m.

The first alert was issued at 9:37 a.m.

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

Virginia Tech Police Chief Wendell Flinchum said that the three children who spotted the alleged gunman were interviewed, and that the information they gave was deemed credible.

The children who reported the sighting were attending a camp called "Higher Achievement."

Higher Achievement CEO Richard Tagle emailed this statement to NBC:

"Higher Achievement can confirm that our scholars were on campus during the situation at Virginia Tech.  The organization was visiting the university as part of our summer academic program for middle-school youth in Washington, DC.  Our first priority is the safety of our scholars and staff.  We have been in contact with them and we have received confirmation that everyone is safe, and are proactively reaching out to parents of students who were on campus. That is all the information we have at this time."

The man in question

Police are searching for a man who fits this description:

-White male

-6-foot tall

-Light brown hair

-Wearing a blue and white striped shirt

-Gray shorts

-Brown sandals

-No facial hair or glasses

"We're in a new era. Obviously this campus experienced something pretty terrible four years ago ... regardless of what your intuition and your experience as a public safety officers tells you, you are really forced to issue an alert, and that's where we believe we are right now," said Larry Hincker, the Virginia Tech spokesman.

Virginia Tech was the site of the 2007 massacre and was criticized for not reacting quickly enough when gunman Seung-Hui Cho killed 32 people on campus that year.

They responded much quicker this time.

"This hits too close to home," managing editor of the campus newspaper Kelsey Heiter told CNN. "But we have a better alert system now. And I have not heard of anybody getting hurt."

Law enforcement officers from VTPD, Blacksburg PD, Christiansburg PD, Virginia State Police, and Montgomery County Sheriff's Office are patrolling the campus, continuing to look for the subject.

"Police have encountered no other witnesses reporting this individual or seeing anything suspicious," the university said.

The campus' latest update asks people to remain secured indoors and report suspicious activity.

Virginia Tech's Updates:

(11:51 a.m.) Update

VT Police in conjunction with four other police departments continue to search the campus for the person reportedly with a weapon.  There have been no other sightings.  We have no further information to report.

We ask people to remain secured indoors.   Report suspicious activity the VT Police Department at 231-6411 or 911.

Update to VT Alerts

(10:35 a.m.) See VT homepage or email for further information on possible person with weapon.  People on campus stay indoors until further notice.

Update to VT Alerts

At 9:09 a.m. three juveniles attending a camp at the university reported seeing a white male, 6 feet tall, with light brown hair outside of New Residence Hall East holding what may have been a handgun.  They say the weapon was covered by a cloth or covering of some sort.  He was walking fast in the direction of the volleyball courts.   He was wearing a blue and white striped shirt (stripes were vertical), gray shorts and brown sandals.  The subject had no facial hair or glasses.

Officers responded immediately to the area but found no one matching the description.  Police have encountered no other witnesses reporting this individual or anything suspicious.  Law enforcement officers from VTPD, Blacksburg PD, Christiansburg PD, Virginia State Police, and Montgomery County Sheriff's Office are patrolling the campus, continuing to look for the subject.

If anyone sees anything suspicious contact the VT Police Department at 231-6411 or 911