A man shot and killed six people and wounded two more during a shooting spree that lasted a few hours and included a high-speed chase in a rural area north of Seattle, local police said.

The suspected shooter was arrested without incident at the Skagit County Sheriff's office after leading Washington state troopers on a chase down a major highway.

Police did not identify the suspect, but said he was from Alger, Washington, a small town 75 miles (120.7 kilometres) north of Seattle. Local media reported that the suspect has a history of mental illness and a criminal past.

"We have multiple crime scenes with multiple victims," said Sgt. Robert Goetz with the Everett police department. "This incident is very large in scope."

One of the victims was a sheriff's deputy, who was responding to an emergency call reporting a person had been shot.

Later, police discovered the bodies of two construction workers a few blocks from where the deputy and the first victim were shot. Police also found another victim in the vicinity and later found a person shot dead in a car off the highway.

The incident is the latest in a series of mass shootings over the last few years in the United States, which is estimated to have the world's highest civilian gun ownership rate, leading gun control advocates to push for tighter restrictions.