A teenager has been arrested on murder charges after two people were shot dead during anti-police protests in the US city of Kenosha, as President Donald Trump said he was sending in additional federal forces.
Violent clashes have erupted in the Midwestern city since a white police officer shot a black man point-blank as many as seven times in his back.
Jacob Blake was trying to get into his car, with his three children inside, when he was shot on Sunday.
It's the most recent police shooting of an African American to spark outrage and protests in US cities as part of the Black Lives Matter movement.
During protests on Tuesday, two people were shot dead and a third injured after a man in civilian clothes with an assault rifle opened fire on demonstrators.
"This morning Kenosha County authorities issued an arrest warrant for the individual responsible for the incident, charging him with First Degree Intentional Homicide," Antioch police said.
"The suspect in this incident, a 17-year-old Antioch resident, is currently in custody of the Lake County Judicial System pending an extradition hearing to transfer custody from Illinois to Wisconsin."
Mr Trump announced that additional federal forces were headed to Kenosha as police try to keep control of the volatile demonstrations.
People gather Tuesday to protest in Kenosha over the shooting of Jacob Blake. Source: AAP
"We will NOT stand for looting, arson, violence, and lawlessness on American streets," Mr Trump tweeted.
"TODAY, I will be sending federal law enforcement and the National Guard to Kenosha, WI to restore LAW and ORDER!"
Mr Trump made the announcement after speaking with Wisconsin Governor Tony Evers, who a day earlier announced he was authorising increased National Guard support for the county to 250 members.
