Philando Castile: Protesters clash with police after officer who killed black man on Facebook Live acquitted

'If we don't get no justice, they don't get no peace,' marchers chanted, later blocking commuter trains and shouting 'Yanez guilty'

Demonstrators march and hold signs along Interstate 94 after a Minnesota police officer was cleared in the fatal shooting of Philando Castile (AP)

Hundreds of protesters took to Minnesota’s streets after police officer Jeronimo Yanez was acquitted of manslaughter for shooting Philando Castile dead.

Officer Yanez killed Mr Castile during a traffic stop last July. His death was broadcast live to Facebook by his girlfriend who was also in the car.

After the officer was cleared of any wrongdoing, protesters took to the streets demanding justice for minorities, shouting "stand up, fight back".

“If we don't get no justice, they don't get no peace," marchers chanted, later blocking commuter trains and chanting "Yanez guilty."

Mr Castile had informed Officer Yanez just seconds before he was shot that he was carrying a gun. He was licenced to have the weapon, and had been told to inform officers of the firearm in those situations for his safety.

Mr Castile had reportedly been reaching for his wallet but the officer testified that Mr Castile was ignoring his commands not to pull out the gun and he feared for his life.

Mr Castile's mother spoke to the media after the acquittal, expressing anger and sorrow with the verdict.

"There has always been a systemic problem in the state of Minnesota, and me thinking, common sense that we would get justice. But nevertheless the system continues to fail black people", she said. "I am so disappointed in the state of Minnesota".

Mr Yanez and his family, meanwhile, quietly slipped out of the courthouse and into a van before leaving without taking questions. Jurors similarly declined to comment on the verdict.

After the rally, police said roughly 2,000 people marched peacefully down streets in the capital St Paul, at times blocking traffic at intersections and then on Interstate 94, a major highway.

The crowd was mixed and included many children, including some who were stencilling posters as the event continued. Some carried signs that read "Unite for Philando" and "Black Lives Matter."

Later a splinter group of scores of protesters walked down a ramp onto Interstate 94. A line of police in riot gear eventually met them, and demonstrators were warned they would be arrested if they didn't disperse.

Additional reporting by agencies