US police have publicly identified a man suspected of driving around the Michigan city of Kalamazoo and randomly shooting people, leaving at least six dead.

Jeff Hadley, Kalamazoo department of public safety chief, named the suspect as Jason Dalton, 45, of Kalamazoo county, the AP news agency reported.

Dalton, an Uber driver, reportedly has no known criminal history. The transport company confirmed that the suspect was one of its employees.

It said in a statement it was "horrified and heartbroken", adding that it offered help in the investigation.

Jeff Getting, Kalamazoo county prosecutor, said authorities were investigating a Facebook post saying the suspect was an Uber driver driving erratically around the time of the shootings.

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Michigan police earlier launched a manhunt after six people were killed and several others injured in seemingly random shootings near a Kalamazoo car dealership and restaurant late on Saturday night.

Michigan police earlier arrested a man whose car matched a description of the suspect's.

Paul Matyas, Kalamazoo county undersheriff, described a rampage that began at about 6pm on Saturday on the eastern edge of Kalamazoo county, where a woman was shot several times and seriously wounded.

A little more than four hours later, a father and his 18-year-old son were fatally shot while looking at cars at the dealership.

Fifteen minutes after that, five people - including the teenage girl who police originally said had been killed, based on a pronouncement by medical officials - were shot in the car park of a Cracker Barrel restaurant along Interstate 94, Matyas said.

Matyas later told the WWMT TV network at the time of Dalton's arrest that the suspect "voluntarily" gave himself up after he was approached by police.

"The threat to the public is over. This is your worst nightmare when you have someone driving around killing people," Matyas said.

Kalamazoo, with a population of about 75,000, is west of Detroit.

It is home to Western Michigan University and the headquarters of popular craft beer maker Bell's Brewery.

The city also is known for the anonymously funded Kalamazoo Promise programme, which for more than a decade has paid for college tuition of students who graduate from Kalamazoo Public Schools.