A gunman has opened fire in downtown Seattle and wounded five people, one man critically, not far from protests over the surprise victory of Republican Donald Trump in the US presidential election.

The shooting did not appear to be related to the anti-Trump demonstrations but instead stemmed from “some type of personal argument”, Robert Merner, assistant chief of the Seattle Police Department, told reporters.

“It appears that some type of argument took place. This individual began to walk away from the crowd, then turned and fired into the crowd,” Merner said.

He said the suspect then fled from the area on foot and remained at large.

Police and fire crews were on the scene in less than a minute because they had been in the area to monitor the demonstrations, he said, but did not arrive in time to engage the suspect.

Police closed down the intersection of Third Avenue and Pine streets, where the shooting took place in front of a 7-11 convenience store.

The Seattle Times newspaper reported that witnesses heard several gunshots.

Thousands of Americans have taken to the streets around the nation to protest Mr Trump becoming president-elect.