Seattle Black Lives Matter clashes spark 45 arrests, 21 police injured

Dozens were arrested and many police injured in clashes around Seattle's biggest Black Lives Matter protest in weeks on Saturday. /Reuters

Dozens were arrested and many police injured in clashes around Seattle's biggest Black Lives Matter protest in weeks on Saturday, police said, with a renewed energy sparked by violent clashes between activists and federal agents in nearby Portland, Oregon.

Police said officers used non-lethal weapons in attempts to disperse the thousands of marchers in the late afternoon after some protesters set fire to the construction site for a King County juvenile detention facility and courthouse.

By 10 p.m.(0500 GMT), police had "made 45 arrests in connection with today's riot in the East Precinct," the Seattle Police wrote in a Twitter post.

It said "21 officers sustained injuries after being struck by bricks, rocks mortars/other explosives. Most officers were able to return to duty. One was treated at a hospital for a knee injury."

(With input from the agencies)