The shooting occurred in the early hours of Saturday morning, Seattle police said in a statement. They added that a 19-year-old man died from his injuries and another male remains in hospital with life-threatening injuries.
"Officers attempted to locate a shooting victim but were met by a violent crowd that prevented officers safe access to the victims," the statement said. "The suspect or suspect(s) fled and are still at large. There is no description at this time."
Police sergeant Lauren Truscott told the local Seattle Times that police were reviewing video footage taken at the scene but had no immediate details about how the shooting unfolded.
Harbourview Medical Centre spokeswoman Susan Gregg said two males with gunshot wounds arrived in a private vehicle at the hospital at about 3am local time. One died and the other was in a critical condition.
The Capitol Hill protest zone (CHOP), originally called the Capitol Hill Autonomous Zone (CHAZ) has become a focal point of demonstrations against racial justice in the city following the police killing of George Floyd in Minneapolis.
The protesters currently occupy the Seattle police department’s East Precinct building, which was abandoned by police after days of clashes. They have largely stayed away from the area since, while local officials have been in regular contact with demonstrators.
The protest zone drew national attention after Donald Trump warned that he would forcibly "take back" the area from what he described as "ugly anarchists". The president has directed similar threats of force at Democratic-run states that are witnessing large-scale demonstrations calling for racial justice.
Seattle's mayor Jenny Durkan hit back at the president at a news conference earlier this month.
“We do not need anyone, including the president, to try to sow further divide, further distrust and misinformation,” Durkan said. “The threat to invade Seattle, to divide and incite violence in our city is not only unwelcome, it would be illegal.”