United Nations human rights officials on Friday called on the United States to stop policing practices nationwide that the officials said disproportionately target black Americans. The U.N. also criticized two separate U.S. grand jury decisions not to indict white police officers who killed unarmed black men suspected of crime.

The United Nations Office of the High Commissioner for Human Rights (OHCHR) said in a statement that they had "legitimate concerns" over two separate U.S. grand jury decisions not to indict the white officers involved in the deaths of unarmed, black men, Michael Brown and Eric Garner.

Garner was stopped on suspicion of selling untaxed cigarettes in July on Staten Island. A bystander recorded on video the black, 43-year-old father of six telling officers to leave him alone before Pantaleo, who is white, put him in a chokehold — a tactic banned by the NYPD since 1993. Garner repeatedly told Pantaleo that he was suffocating prior to his death, repeating the words "I can't breathe."

The grand jury’s decision in Garner’s case came almost a week after another grand jury declined to indict a white policeman for fatally shooting unarmed black teenager Michael Brown in Ferguson, Missouri in August. The two incidents have helped stoked the fires of longer-running efforts to combat police brutality, particularly against black Americans.

"The Michael Brown and Eric Garner cases have added to our existing concerns over the longstanding prevalence of racial discrimination faced by African-Americans, particularly in relation to access to justice and discriminatory police practices," said Mireille Fanon-Mendes-France, the OHCHR’s chairperson of the Working Group of Experts on People of African Descent.

U.S. Attorney General Eric Holder has launched a civil rights probe of the Brown shooting and also promised an investigation of the Garner case in New York — both of which sparked protests across the U.S.

Still, Fanon-Mendes-France together with other U.N. human rights officials said that if the grand juries had brought the officers in Brown and Garner's deaths to trial, it would have brought all the evidence to light and allowed justice to "take its course."

"I am concerned by the grand juries' decisions and the apparent conflicting evidence that exists relating to both incidents," said Rita Izsak, U.N. special rapporteur on minority issues. "The decisions leave many with legitimate concerns relating to a pattern of impunity when the victims of excessive use of force come from African-American or other minority communities."

According to international law, the use of lethal force is only permissible in cases where it is absolutely necessary to protect life, said Christof Heyns, U.N. special rapporteur on extrajudicial, summary or arbitrary executions.

"The laws of many of the states in the U.S. are much more permissive, creating an atmosphere where there are not enough constraints on the use of force. A comprehensive review of the system is needed – the enabling laws, the kinds of weapons the police use, the training they receive and the use of technology such as on-body cameras to ensure accountability," Heyns said.

Mutuma Ruteere, a Kenyan serving as U.N. special rapporteur on contemporary forms of racism, called for action to address the many complaints of discriminatory practices including racial profiling by police officers.

"There are numerous complaints stating that African Americans are disproportionately affected by such practices of racial profiling and the use of disproportionate and often lethal force," Ruteere said. "African Americans are 10 times more likely to be pulled over by police officers for minor traffic offenses than white persons. Such practices must be eradicated."

With wire services