A gunman allegedly shot 21 people, killing five, inside a lecture hall Thursday (February 14) at Northern Illinois University's DeKalb campus, authorities said. The shooter killed himself after the spree, according to police.

Around 3 p.m. CT, the gunman walked out from behind a screen in a 600-seat lecture hall and opened fire, NIU President John Peter told CNN. The gunman was armed with a shotgun and two handguns and was dressed in all black, DeKalb Police Chief Donald Grady said. "It started, and it stopped very quickly," Grady reportedly said.

Grady also told CNN that police know the identity of the gunman but are not yet releasing the information. He was not a student at the DeKalb campus, located just outside Chicago, Grady said, adding that police do not yet have a motive.

A spokesperson for the Kishwaukee Medical Center, where many of the victims were transported for medical treatment, said the hospital has received a total of 13 patients, four of whom sustained serious head wounds. One student was airlifted to another nearby hospital. At press time at least three victims were in critical condition, eight in stable condition and six in good condition, according to CNN.

CNN spoke with a student who claimed to be inside the classroom when the gunfire began to erupt. According to the student, the gunman kicked open the door to one of the lecture halls and fired off shotgun blasts at the fleeing students from the front of the classroom. It is believed the shooter fired off 30 rounds before dropping the shotgun and turning to a pistol he was also carrying.

The school's Web site confirmed the presence of a shooter on the DeKalb campus within minutes but made no mention of the reported dead. "It has been confirmed that there has been a shooting on campus and several people have been taken away by ambulance," the site reads. "All classes are canceled on the DeKalb campus. People are urged not to come to campus. More information will be posted as it becomes available." Friday classes at the school's DeKalb campus have also reportedly been canceled, and counseling areas have been set up across the campus.

According to CBS station WBBM-TV, the NIU campus went on lockdown soon after the initial reports of shots being fired at the school. The station reported that several ambulances responded soon after the incident. According to CNN, Illinois Governor Rod Blagojevich later declared a state of emergency, enabling him to allow the governor's disaster fund so that local government entities can be reimbursed for "extraordinary expenses related to the response in NIU DeKalb." The move will also reportedly allow the state Emergency Management Agency to provide assistance as well.

The school's student newspaper, the Northern Star, reports that the gunman shot five people before turning the gun on himself, but police have yet to confirm that claim. The shootings reportedly occurred at the King Commons, a central gathering point for the entire campus, and the alleged shooter has been described as a white male.

One student, George Gaynor, told the Star the shooter was "a skinny white guy with a stocking cap on." He described the scene outside Cole Hall as chaotic. "Some girl got hit in the eye, a guy got hit in the leg," Gaynor told the student paper. "It was like five minutes before class ended too."

[This story was originally published at 5:35 p.m. ET on 2.14.2008]