The city of Milwaukee imposed a 10 p.m. curfew on Monday in an attempt to quell rioting that erupted the previous two nights in response to the police shooting of an armed black man in one of the most segregated cities in the United States.

Mayor Tom Barrett also renewed his call for state officials to release a video of the Saturday night shooting in hopes it convinces angry protesters that deadly force against Sylville K. Smith, 23, was justified.

"There is a curfew that will be more strictly enforced tonight for teenagers," Barrett told a news conference. "So parents, after 10 o'clock your teenagers better be home or in a place where they're off the streets."

Milwaukee has become the latest American city to be gripped by violence in response to police killings of black men in places such as Ferguson, Missouri, in 2014 and Baltimore last year.

Famed for its breweries, Milwaukee is also one of the most segregated cities in America, with a large concentration of unemployed black men in the inner city separated from the mostly white suburbs.

Such inequality has afflicted many US cities as a result of the loss of manufacturing jobs over the past three decades, sometimes stoking unrest when police use deadly force.

Police say Smith was stopped on Saturday afternoon for behaving suspiciously and that he then fled on foot between two homes. Smith was carrying a stolen handgun which he refused to drop when he was killed, police said.

The shooting led to a first night of protests over his death in which gunshots were fired, six businesses were torched and 17 people were arrested. Police reported four officers were injured and police cars were damaged before calm was restored.

On Sunday night, when police in riot gear faced off with protesters throwing bottles and bricks, four officers were injured and one other person suffered a gunshot wound, police said. Three police squad cars were damaged and 14 people were arrested, authorities said.

Wisconsin Governor Scott Walker had activated the National Guard on Sunday in case more trouble flared, but despite the violence, police said the guardsmen were not called in.

This weekend's shooting in Milwaukee was distinct in that the deceased was armed, according to the police account. The officer who fired the deadly shot was also black.

The mayor would like Wisconsin state officials to release the video to the public in order to corroborate the police account. State law requires all police shootings to be investigated by an independent state agency, giving the state control over such evidence.

"I want the video released. ... I'm going to urge that it be released as quickly as possible," said Barrett, who has yet to see it.

Police Chief Edward Flynn said on Sunday that video from the officer's body camera showed Smith had turned toward the officer with a gun in his hand.

The video appeared to show the officer acting within the law, Flynn said, but because the audio was delayed it was unclear when the officer fired his weapon.

Police had stopped Smith's car, leading to a chase on foot.

Police said Smith's car was stopped because he was acting suspiciously, raising skepticism within largely African-American neighborhoods where people report racial discrimination from police. Smith also had a lengthy arrest record, officials said.

Asked at the news conference why officers had stopped the car on Saturday, Police Chief Edward Flynn said the officers had not been interviewed yet and that they would be interviewed later on Monday.