An officer-involved shooting in in the US city of Milwaukee sparked angry protests on Saturday night. (AP photo)

A standoff between police and protesters in the US city of Milwaukee has turned violent after a police officer fatally shot a man during a foot chase.
An angry crowd gathered Saturday night in the neighborhood where the shooting took place. Police officers, some of them in riot gear, amassed the area.
Some protesters reportedly started smashing a police car’s windows and another vehicle was set on fire.
Police tweeted that an officer was being treated for an injury after he was hit by a brick thrown through a squad window.
Later in the evening, a gas station was set on fire and firefighters could not get close to the blaze because of gunshots.
The shots appeared to be fired in the air by someone in the crowd.
Authorities said officers stopped two suspects in a car about 3:30 p.m. The suspects tried to escape on foot. During the pursuit, a six-year veteran of the department shot and killed one of the suspects.
"That officer had to make a split-second decision when the person confronted him with a handgun," Milwaukee Police Assistant Chief Bill Jessup said. "This is a risk they take every day on behalf of our community."
Police have not identified the man but said he was carrying a semiautomatic handgun.
The officer, who fired the shot, will be placed on administrative duty during the investigation, police said.
The incident came amid renewed anger over the fatal shooting of several young African-American men by police around the US in recent weeks.
The ongoing spate of police violence has sparked fresh protests throughout the country.
Police killed over 1,150 people in 2015, with the largest police departments disproportionately killing at least 321 African Americans, according to data compiled by an activist group that runs the Mapping Police Violence project.