A protester has died, and another left seriously injured, after a car drove onto a closed road and struck two people protesting against police brutality in Seattle. 

Summer Taylor, 24, of Seattle died in the evening at Harbourview Medical Centre, local authorities have confirmed. 

Taylor and Diaz Love, 32, of Portland, Oregon, were hit by the car that barrelled through a panicked crowd of protesters on Interstate 5 early on Saturday morning, officials said.

Dawit Kelete of Seattle drove the car around vehicles that were blocking the road and sped into the crowd at around 1.40am, according to a police report released by the Washington State Patrol.

Video taken at the scene by protesters showed people shouting “Car! Car!” before fleeing the road.

Love is in serious condition in the intensive care unit, spokesperson Susan Gregg confirmed. 

Love was filming the protest in a nearly two-hour-long Facebook livestream captioned “Black Femme March takes I-5” when the video ended abruptly. With around 15 seconds of the footage left, shouts of “Car!” can be heard as the camera starts to shake before screeching tyres and the sound of impact are heard.

A graphic video posted on social media showed the white Jaguar racing toward a group of protesters who are standing behind several parked cars, set up for protection.

The car swerves around the other vehicles and slams into the two protesters, sending them flying into the air.

The driver, who was alone, fled the scene after hitting the protesters, Trooper Chase Van Cleave said.

One of the other protesters got in a car and chased the driver for about a mile. He was able to stop him by pulling his car in front of the Jaguar, Van Cleave said.

Troopers arrived, and the driver was put in custody, Washington State Patrol Captain Ron Mead said.

Kelete was described by offices as reserved and sullen when he was arrested, and asked whether on not the pedestrians were okay, according to court documents.

Kelete was booked into the King County Correctional Facility on two counts of vehicular assault. Bail was denied. A judge later found probable cause to hold Kelete on an investigation of vehicular assault.

He faces a second court hearing on Monday at which the judge will determine if he can be released on bail, according to court documents. It was not immediately clear if Kelete had a lawyer who could speak on his behalf.

Officials were trying to determine the motive as well as where he got onto the interstate, which had been closed by the state patrol for more than an hour before the protesters were hit. Mead said police suspected that Kelete had driven the wrong way on a ramp.

Troopers did not know whether it was a targeted attack, but impairment was not considered a factor, Mead confirmed.

He is listed in public records as a student who attended Washington State University between 2011 and 2017 majoring in business and commerce. His enrolment status could not be confirmed because the university was closed on Saturday.

Seattle has been the site of prolonged unrest following the May 25 police killing of George Floyd in Minneapolis, which sparked nationwide protests.

Dozens of people were arrested this past week in connection with protests as demonstrations continue after authorities cleared the Capitol Hill Occupied Protest zone on Wednesday morning.

Protesters had shut down the interstate for 19 days in a row, Mead said at a press conference.