After an extensive search for a suspected gunman on Virginia Tech's campus Thursday, authorities have lifted the alert advising everyone on campus to stay safely indoors.

"The campus alert is lifted. There will continue to be a large police presence on campus today," the university said in a notice posted at 2:41 p.m. "Police have not received nor discovered additional information about a person possibly carrying a weapon beyond that reported this morning."

Three teenaged academic campers reported seeing someone carrying what appeared to be a gun near Dietrick Hall at the Blacksburg, Va., campus Thursday morning. After verifying the credibility of the information given, the school issued a campuswide alert shortly after 9:30 a.m., the Richmond Times-Dispatch reported.

"We have not had any reported sightings or any more information regarding this person,"  Tech Police Chief Wendell Flinchum told reporters at a news briefing this morning.

"We're in a new era,"  Virginia Tech spokesman Larry Hincker added. "Obviously this campus experienced something terrible four years ago."

Flinchum maintained in an afternoon press conference that police had considered the initial report credible.

"They [the three teenage girls] gave us a good description. We felt it was best course of action to issue a campus alert," Flinchum said.

"I think the girls believed what they reported. The officers believed they (the girls) believed what was reported and that's the information they went with."

In April 2007, Virginia Tech English major Seung-Hui Cho killed 33 people in a rampage that ended with his own suicide. The school has been widely criticized for waiting two hours and fifteen minutes to issue a warning after two students were slain by the gunman.

Virginia Tech is currently appealing $55,000 in fines for federal violations U.S. Department of Education in March found the school in violation of the Clery Act, Richmond Times-Dispatch reports.