A gunman killed six people in a shooting spree in the northern US state of Michigan, police said Sunday, after arresting an armed 45-year-old white male for the crime.

Officials corrected an earlier report of seven dead, stating that one of the victims was alive but seriously injured.

The suspect was apprehended at 12.40am on Sunday (0540 GMT) after the shooting rampage Saturday night in the city of Kalamazoo, police said.

Michigan state trooper Lieutenant Dave Hines told a post-midnight press conference that there were three separate shootings – one outside an apartment complex, another outside a car dealership, and the third at a chain restaurant.

"What it looks like is we have somebody driving around, finding people and shooting them dead in their tracks," Kalamazoo County Undersheriff Paul Matyas told the local CNN affiliate 24 Hours News 8.

"This is your worst nightmare, when you have somebody just driving around randomly killing people," he added.

At a later press conference at sunrise Kalamazoo County prosecutor Jeff Getting identified the white male suspect as Jason Brian Dalton, 45, and said that he will face murder charges in court on Monday.

Getting said Dalton is accused of shooting eight people, six of whom died. Earlier reports of the death of seventh victim, a teenage girl, were incorrect, Getting said, though he did say that the teen was "gravely injured."

The gunman's motives were unclear, officials said.

Several police agencies were involved in the case, and the death toll and profiles of those killed changed as the hours went by and details emerged.

The suspect was armed when he was arrested at a traffic stop, but surrendered peacefully, Matyas said.

Kalamazoo, in the northern state of Michigan, is located some 190 kilometers (160 miles) west of the industrial city of Detroit and has a population of 76,000, according to census figures.

The Kalamazoo killings follow a pattern of mass shootings in the United States that include the December 2 massacre in San Bernardino, California that left 14 people dead and 22 wounded, and the December 14, 2012 Sandy Hook school massacre in which 20 children and six adults were shot dead.

Gun violence kills about 30,000 Americans every year and mass shootings – rare in most countries – have been on the rise in the United States.

According to the tracking website gunviolencearchive.org, there were 330 mass shootings in the United States in 2015, up from 281 in 2014. They affected nearly every part of the country, reaching into both big cities and small towns.