The university has advised everyone on campus to "seek shelter or stay where you are" because of reports about shots being fired there.

There's a tense situation happening now on the campus of Virginia Tech in Blacksburg, Va., where shots have been fired, a suspect is still at large and a police officer and one other person are reported to have been killed.

The school has advised everyone on campus to "seek shelter or stay where you are."

It adds that:

"[A] suspect described as white male, gray sweat pants, gray hat w/neon green brim, maroon hoodie and backback" was seen "on foot towards McComas" —one of the university's athletics facilities.

The university was the site of a mass shooting in April 2007, during which a student killed 32 other people before taking his own life. We'll be updating this post as the story develops, so be sure to hit your "refresh" button. And as always in situations where things are happening quickly, there will be conflicting reports. We'll try to sort through the confusion and only pass along the best reporting based on reliable sources and outlets.

Update at 3:35 p.m. ET. Map With Location Of Incidents:

The student-run Collegiate Times has a map posted here that shows the locations on campus where the two deaths occurred.

Update at 3:15 p.m. ET. Witness Saw Police Rush To Mortally Wounded Officer:

WDBJ-TV spoke with a young woman who said she had just left a building and was walking toward the unmarked police car when "the police pulled up and they opened his car door and when they opened it, he just fell out towards the ground."

"I guess the officer didn't make it, because they just covered him with the sheets," she added.

Update at 3:10 p.m. ET. Exams Postponed; Mood "Fairly Calm":

"Exams scheduled for tomorrow have been postponed, according to Virginia Tech," the student-run Collegiate Times says. It also reports that the "mood inside Squires [Student Center] lockdown room is fairly calm, talkative."

Update at 3:05 p.m. ET. School Created "Advanced Security Alert" after 2007 Tragedy:

The Washington Post reminds readers that "Virginia Tech, a public campus of about 30,000 students, has one of the nation's most advanced security alert systems, installed after the nation's worst campus shooting, a 2007 rampage by student Seung-Hui Cho that left 32 dead. University officials were criticized for not locking down the campus that day and have dramatically overhauled their alert system. The entire campus was on lockdown Thursday."

Update at 2:55 p.m. ET. Connection To Earlier Armed Robbery?

There was an armed robbery and car theft Wednesday in Radford, Va., about 20 miles from Blacksburg. The suspect was described as a white male, "wearing dark colored clothes and a dark colored baseball style cap." University spokesman Mark Owczarski told reporters earlier it's too soon to say whether that incident is related to today's.

Update at 2:45 p.m. ET. News Conference At 4:30 P.M. ET:

The university says it plans to hold a news conference at 4:30 p.m. ET.

Update at 2:42 p.m. ET.

Mark Owczarski, a university spokesman, is talking to reporters now (webcast here). He says "the status of the shooter" is still unknown. The identity of the second person who was killed isn't yet known, he says.

Update at 2:30 p.m. ET. Photos:

The student-run Collegiate Times has put some photos on Flickr. Several are of police officers on the scene. Reminder: Collegiate Times is following the story on Twitter ... @collegiatetimes.

Update at 2:25 p.m. ET. Reports Of More Shots "Unfounded":

The university posts that:

"Numerous reports have been made recently of sounds identified as gunshots and suspicious activity on campus. These recent reports have been investigated and are unfounded. The suspect's status remains unknown. Several law enforcement agencies are on scene to assist. Please stay where you are and secure your surroundings."

Update at 2:08 p.m. ET. Another Source:

On Twitter, @BlacksburgStuff is following the news. It says "the media should know that today is 'Reading Day' and there are no classes or exams today."

Update at 1:58 p.m. ET. The Latest Statement From The University:

"Shortly after noon today, a Virginia Tech police officer stopped a vehicle on campus during a routine traffic stop in the Coliseum parking lot near McComas Hall

"During the traffic stop. the officer was shot and killed. There were witnesses to this shooting.

"Witnesses reported to police the shooter fled on foot heading toward the Cage, a parking lot near Duck Pond Drive. At that parking lot, a second person was found. That person is also deceased.

"Several law enforcement agencies have responded to assist. Virginia State Police has been requested to take lead in the investigation

"The status of the shooter is unknown. The campus community should continue to shelter in place and visitors should not come to campus."

Update at 1:55 p.m. ET. Began As "Routine Traffic Stop":

The university has also reported, WDBJ-TV says, that the incident began with a "routine traffic stop."

Update at 1:53 p.m. ET. Two People Killed:

WDBJ-TV reports that the university says the police officer was killed and that a second person has been found dead nearby in a parking lot.

Update at 1:47 p.m. ET. That Person Wasn't Arrested:

Collegiate Times updates to say the man it posted about a few minutes ago "is not under arrest."

Update at 1:45 p.m. ET. Suspect Possibly Caught?

The student-run Collegiate Times is reporting that a man who may be the suspect may have been apprehended. Collegiate Times' Twitter page is here.

Update at 1:35 p.m. ET. Traffic Stop?

Local WSLS-TV writes that "NBC's Pete Williams is reporting that there was a traffic stop, and gun shots were fired during that traffic stop."

Update at 1:20 p.m. ET. Webcast:

WDBJ-TV is streaming its coverage here. It says the first report of shots came around 12:30 p.m. ET.

Update at 1:16 p.m. ET. Officer And Possibly A Second Person Shot:

The university's website now says:

"Suspect remains at large. A police officer has been shot. A potential second victim is reported at the Cage lot. Stay indoors. Secure in place."

Update at 1:15 p.m. ET. Officer Reportedly Shot:

WDBJ-TV in Roanoke says its reporter Karen Kiley says "a police officer is the one who has been shot." [Copyright 2011 National Public Radio]