At least three people were killed and five injured after a gunman opened fire at Michigan State University on Monday night, as law enforcement swarmed the main campus in East Lansing searching for a lone suspect, police said.

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 shooting, which began shortly after 8 p.m. Eastern time, found victims at both locations, Rozman told reporters at a televised late-night briefing about three hours later.

He confirmed that at least five victims were transported to the hospital, some of them with life-threatening injuries, and MSU police issued an update by Twitter a short time later saying that at least three additional people had been killed, stated reports.

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 neighborhoods of East Lansing, about 90 miles 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.

University police said Monday night that all classes and campus activities would be cancelled for the next 48 hours.