A large police presence will remain on the Virginia Tech campus after an extensive police search for a man with a gun on Thursday yielded nothing.

According to the school's Web site, around 9:37 a.m. there were reports of a person with a gun and students were told to stay inside and that emergency personnel were responding.

At around 2:41 p.m. the school's site had a notification stating that the alerted has been lifted.

"There will continue to be a large police presence on campus today," according to the post. "Police have not received nor discovered additional information about a person possibly carrying a weapon beyond that reported this morning. The university community may resume normal campus activity. Only Blacksburg campus classes have been cancelled today."

The campus lockdown was lifted about five hours after the initial report from three teens who said they saw a man carrying what may have been a gun covered with a cloth on the campus. The 2,600-acre campus was the site of a mass shooting in 2007 that left 33 people dead.

Police searched over 150 campus building for the alleged gunman but came up empty, according to reports.

Classes were cancelled for the day when the university declared a lockdown.   

"The juveniles were interviewed ... officers confirming that their information is credible and at that point we decided to issue the alert," Virginia Tech Police Chief Wendell Flinchum said.

And police released a sketch of the gunman, who is described as a 6-feet tall man with light brown hair.

Police said the man was wearing a blue and white striped shirt, gray shorts, and brown sandals. Flinchum said that the man was not pointing or shooting the weapon.

Virginia Tech officials also warned students of the possible gunman through text messages and emails.   

"This campus experienced something terrible four years ago," campus spokesman Larry Hincker said in a press conference.

"Strictly as an abundance of caution we are going to keep the campus under alert status and ask people to stay indoors," he added.

Here are the alerts students received throughout the incident.

BLACKSBURG, Va., Aug. 4, 2011 - 2:41 p.m. Update to VT Alerts

The campus alert is lifted. See email or www.vt.edu for further information.

The campus alert is lifted. There will continue to be a large police presence on campus today.  Police have not received nor discovered additional information about a person possibly carrying a weapon beyond that reported this morning.  The university community may resume normal campus activity. Only Blacksburg campus classes have been cancelled today. 

While the alert has been lifted, as always, we suggest that people remain vigilant and report suspicious campus activity to Virginia Tech Police at 911 or 540-231-6411.

1 p.m. Update to VT Alerts

Crime Alert: Person with gun reported at Dietrick; emergency responders on scene

Campus alert remains in effect.  We recommend that students, employees, and others on campus remain secured indoors. Classes are cancelled for remainder of the day. Students are asked not to come to campus.

The university understands that it has been several hours since this began. Many officers from many police departments continue to search campus buildings. We have a very large campus and this will be a long process. There have been no further sightings or reports.

Police have released a composite of the person who was sighted earlier today and is posted on www.vt.edu.  If you believe that you are this person and that your activity was mistaken, please contact Virginia Tech Police at 540-231-6411.

We will continue to update you this afternoon.

11:51 a.m. Update to VT Alerts

Police continue to investigate campus. There have been no other sightings. We ask people to remain secured indoors.

Update

Virginia Tech 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 Virginia Tech Police Department at 231-6411 or dial 911.

10:31 a.m. Update to VT Alerts

See the Virginia Tech 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 the Virginia Tech Police Department, Blacksburg Police Department, Christiansburg Police Department, 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 Virginia Tech Police Department at 540-231-6411 or dial 911.

Campus indviduals should remain indoors.

10:08 a.m. 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 Virginia Tech Police Department, Blacksburg Police Department, Christiansburg Police Department, 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 Virginia Tech Police Department at 540-231-6411 or 911.

9:37 a.m. VT Alert

Person with a gun reported near Dietrick. Stay inside. Secure doors. Emergency personnel responding. Call 911 for help.