Authorities in Cleveland warned Sunday they would not tolerate violent protests over the acquittal of a white policeman in the fatal shooting of two African Americans, after dozens of people were arrested.

Small, mainly peaceful protests erupted Saturday in the midwestern U.S. city and dragged on into the night after 31-year-old patrolman Michael Brelo was found not guilty on two counts of voluntary manslaughter in the 2012 killing. 

A Cleveland patrolman who fired down through the windshield of a suspect's car at the end of a 137-shot barrage by police officers that left the two unarmed black occupants dead was acquitted Saturday of criminal charges by a judge who said he could not determine the officer alone fired the fatal shots.

Michael Brelo, 31, put his head in hands as the judge issued a verdict that prompted an angry protest outside the courthouse, including chants of "Hands up! Don't Shoot!"

An investigation into the police shooting of a 12-year-old African-American boy is taking so long that he has yet to be buried five months after his death, lawyers said Monday.

Tamir Rice was holding a pellet gun when he was fatally shot on November 22 in a Cleveland playground, in a shocking incident caught on surveillance video.

A three-year-old boy in Cleveland killed a baby on Sunday when a gun that he picked up went off and hit the one-year-old in the face, U.S. media reported.

Investigators are trying to determine where the gun, left unattended in the house, came from,  Cleveland.com reported, citing police.

The Justice Department is announcing new limits Monday on racial profiling, after a string of unarmed blacks at the hands of white police officers that have stirred widespread protests.

Except for cases involving terror suspects, federal law enforcement agencies will face a broader ban on controls and arrests based on race, ethnicity, nationality, religion, sex or sexual orientation, officials said.

A U.S. federal probe has concluded that the police in Cleveland -- where a 12-year-old boy was recently shot and killed by police -- has engaged in a pattern of "using excessive force," Attorney General Eric Holder announced Thursday.

The announcement came amid rising racial tensions over a series of police killings of African Americans, most recently that of Tamir Rice, who was shot to death last month in a Cleveland playground by police responding to reports of a boy brandishing a gun. Rice was later found to have a toy gun.

U.S. police officers shot dead a 12-year-old black boy carrying a replica gun within seconds of their patrol car arriving on the scene, a surveillance video released Wednesday showed.

The sudden end to the incident has stoked anger at police tactics in the United States, in the wake of rioting triggered by a decision not to prosecute a white officer who killed an unarmed black teenager.

The chief of police in the U.S. city of Cleveland on Monday defended the conduct of an officer who fatally shot a 12-year-old boy who was wielding a replica handgun.

Tamir Rice died in hospital early Sunday after two police officers, responding to a 911 emergency call, confronted the African-American youngster at a recreation center.

Police in the U.S. city of Cleveland shot and killed a 12-year-old boy who was in a playground waving around what turned out to be a replica gun, officials and reports said Sunday.

Officers called to the scene Saturday fired at the boy twice, hitting him at least once in the stomach, after reports that he was pointing a gun at people. 

Ariel Castro, the man accused of holding three young women captive for a decade, had a history of violence and threatening behavior, U.S. police reports released Monday showed.

But while police questioned Castro on at least eight occasions -- including twice while the kidnapped women were trapped in his Cleveland, Ohio home -- he was never charged with a crime.