Few official details about the gun violence were immediately available, but Chris Rozman, interim deputy chief of the university police, said shots were fired in two locations - at an academic building called Berkey Hall and the Michigan State University Union building.
Police responding to the Monday night shooting found victims at both locations, Rozman told reporters at a televised late-night briefing.
He confirmed that at least five victims were taken to the hospital, some of them with life-threatening injuries, and MSU police issued an update by Twitter a short time later saying at least three additional people had been killed.
Hours after the first gunfire erupted, several campus buildings had been cleared and secured by police as officers swept the campus in search of possible additional victims and a single suspect, MSU police said.
Students, faculty and residents in surrounding off-campus neighbourhoods of East Lansing, about 140 kilometres northwest of Detroit, were urged by authorities to "shelter in place" while the manhunt continued.
The suspect, initially described as a short male wearing a mask, was last seen fleeing the MSU Union building on foot, Rozman said.
MSU is a major public institution of higher education whose flagship East Lansing campus accounts for 50,000 graduate and undergraduate students.
University police said Monday night that all classes and campus activities would be cancelled for the next 48 hours.
Monday night's violence came roughly 14 months after a deadly mass shooting on November 30, 2021, at Oxford High School in Oakland County, Michigan, about 130 kilometres east of East Lansing, in which a 15-year-old student opened fire with a semi-automatic pistol.
Four classmates were killed and six other students and a teacher were wounded in that attack, the deadliest US school shooting that year.
Authorities said the teenage suspect, who has pleaded not guilty to murder charges, used a gun his parents bought him as a Christmas present despite signs that he was emotionally disturbed.
Both parents were charged with involuntary manslaughter in the case.
Governor Gretchen Whitmer said on Twitter that she was being briefed on the East Lansing shooting.
