Courtesy of CNN:

Two people, including a Virginia Tech police officer, were dead after a shooting incident on Virginia Tech’s campus in Blacksburg earlier this afternoon., the university said.

Witnesses saw the police officer being shot during a traffic stop on campus, and the second victim was found dead at a nearby parking lot toward which the gunman had been seen fleeing, the university said. The status of the shooter was not immediately known, and the campus was on lockdown Thursday afternoon, spokesman Mark Owczarski said.

The incident comes more than four years after a shooting spree in which a Virginia Tech student, 23-year-old Cho Seung-Hui, shot dead 32 people on the campus before killing himself in April 2007.

The following are running updates on Thursday’s incident:

[Updated 2:46 p.m. ET] Tauhid Chappell, a student on campus, told CNN that he and other students were getting information through the school alert system, and through the web and radio.

Things felt “very quiet and still,” he said. Classes for the semester ended Wednesday. Students were preparing Thursday for final exams.

[Updated 2:45 p.m. ET] A university spokesman says police have a description of a suspect and are searching “absolutely everywhere for the person who matches the description.”

The campus is on lockdown, and people on campus are urged to “shelter in place,” the spokesman said. The university is urging that no one visit campus, he said.

[Updated 2:10 p.m. ET] Six agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives are at Virginia Tech to help with the response to Thursday’s shooting, ATF spokesman Scot Thomasson said, according to CNN’s Carol Cratty. Twenty additional agents are on standby, he added.

“The agents are very familiar with the campus and the buildings” because they have worked with Blacksburg police since the 2007 mass shooting on campus, Thomasson said.

[Updated 2:07 p.m. ET] The staff of the Collegiate Times newspaper has been evacuated from its offices in the Squires Student Center on the Virginia Tech campus, the paper’s Twitter feed reports.

[Updated 1:56 p.m. ET] A Virginia Tech police officer has been shot and killed after making a traffic stop on the university’s campus, Mark Owczarski, the university’s director of news and information, said Thursday.

The suspect fled on foot toward another parking lot where a second person was also found dead, he said.

The shooter is still at large, he said.

[Updated 1:39 p.m. ET] Sirens were heard around the Virginia Tech campus Thursday, and rescue workers were trying to resuscitate a person who was on the ground, school employee Brian Walls told CNN. The school was on lockdown after shots were reported, and the school’s website said a police officer was shot.

Follow the incident via the Twitter feed of the school’s newspaper, the Collegiate Times. These reports have not been confirmed by CNN.

[Updated 1:16 p.m. ET] A police officer has been shot on or near the campus of Virginia Tech, the university’s website says. A possible second victim is reported down in a parking lot and the suspect is at large, the website says.

Classes for the semester ended Wednesday. Students were preparing Thursday for final exams.

[Posted 1:01 p.m. ET] The campus of Virginia Tech University in Blacksburg is on lockdown after a report of shots being fired on the campus.

The suspected shooter is described as a white male wearing gray sweat pants, a gray hat with a neon green brim and a maroon hoodie and carrying a backpack, according to the university’s website.

Those on campus should seek shelter or stay where they are, the website says.

In April 2007, Cho Seung-Hui, a 23-year-old Virginia Tech student, shot dead 32 people on the campus before killing himself.