Two people were stabbed at Rutgers University's business school on the Livingston College campus in Piscataway, the college says.
The school tweeted out an alert shortly before 3 p.m. Friday saying there had been a stabbing at the business school on the campus and urging students and faculty to avoid the area and take shelter.
Students on campus say it happened on the fifth floor of the business building, near a lounge where students were studying.
"I just hear yelling, and like sort of a struggle go down, then people started getting up looking frantic," said Stephen Mourad of Edison.
Sophomore Nathan Gabriel said he saw a woman in a chair, and a lot of blood.
"I saw professors bring her towels to put on the wound, to apply pressure," he said.
A current student and a professor were stabbed, the prosecutor's office says. Rutgers said the man with a knife was a former student, and witnesses said he may have been trying to hurt himself.
The two stabbed victims, along with the man with the knife, were all taken to Robert Wood Johnson University School in New Brunswick to be treated for their injuries, authorities said.
A lockdown on campus was lifted a short time later.
There are more than 40,000 students enrolled at the New Brunswick campus, the largest of the state university's three locations.