Protesters threw rocks at police in Salt Lake City, Utah after officers shot a black Muslim American teenager multiple times which has left him in a coma since Saturday.

Relatives of the 17-year-old victim, identified as Abdi Mohamed, told a local news network that he was in critical condition at a hospital after being shot three times.

The shooting unleashed protests on Saturday in downtown Salt Lake City, where angry demonstrators gathered near the shooting scene to shout at police and throw rocks at officers.

Nearly 100 officers, some of them carrying riot shields, responded with pepper spray and Tasers.

Family members said that Mohamed had lived in Utah for the past decade and had a son. They described him as a nonviolent person.

Selam Mohammad, 19, said he was a witness and told reporters his friend, the teenager who was shot, had been fighting with an older man and was shot as he turned to face police.

"He barely even turned around. ... My friend didn't do anything," Mohammad said.

The shooting came as police departments across the United States face increased scrutiny over allegations of excessive force against black people and other minority groups.

Police in the United States have 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.

The report also said charges against police officers who do use deadly force are very rare and that police use of lethal force is not correlated to violent crime rates.