Three dead, 5 wounded in US campus shooting

A gunman who killed at least three people and wounded five on a US university campus shot himself dead after a massive police manhunt.

Thousands of students at Michigan State University were ordered to shelter in place after shots were fired in a campus building in the early evening, leaving two dead.

The gunman fled to the students' union, where he killed one more person, sparking a major police operation as officers swarmed the 5,000-acre campus.

Just after midnight, police confirmed the suspected gunman had shot himself dead a short distance away.

"We are sad to report that there have been three confirmed fatalities," Deputy Chief Chris Rozman of the university's police force told reporters.

"This is in addition to the five victims who were injured and transported to the hospital. Some of those five victims still have life-threatening injuries."

Rozman said hundreds of officers from several agencies had been involved in the operation to try to find the gunman, releasing a photograph of a Black man in a baggy blue jacket, and wearing red shoes.

The "suspect has died from a self-inflicted gunshot wound."

Gun violence is alarmingly common in the United States, a country where there are more guns than people and where attempts to clamp down on their spread are always met with stiff resistance.

Tens of thousands of people die every year after being shot, and many more are wounded.

Michigan State University officials said all campus activities would be cancelled for the next 48 hours.