Police in the US city of Columbus in Ohio fatally shot a black teenage girl they confronted during an attempted stabbing, as seen in police video footage of the encounter, authorities said.
The incident, sparking street protests in Ohio's largest city, came as the nation was focused on the guilty verdict a Minneapolis jury returned against a white former Minneapoli police officer charged with murdering George Floyd last year by kneeling on his neck.
Releasing police body-camera video of yesterday's shooting, the interim Columbus police chief, Michael Woods, said officers involved were responding to an emergency call from someone who reported an attempted stabbing at a home on the city's southeast side.
Arriving police encountered a chaotic scene of several people on the front lawn where a teenager, holding a knife, charged toward one female who falls backwards, then lunged at a second female, the video showed.
During the incident a police officer opens fire and the girl is seen collapsing on the ground.
Family members have identified her as Ma'Kiah Bryant, aged 16.
The police chief said the video was released to the public within hours of the incident in the interest of "transparency".
The officer who opened fire was not identified but appears from the video to be white. The chief said he "would be taken off the street" pending an investigation.
Around the time the video was made public, live television news coverage showed a growing crowd of protesters on city streets after dark, confronting a small line of police officers on bicycles.
The demonstration appeared from media coverage to be peaceful, with protesters repeatedly chanting the girl's name.
The Columbus Dispatch newspaper reported that demonstrators had gathered near the scene of the shooting earlier in the day.
Mr Woods said the Ohio Bureau of Criminal Investigation (BCI) had opened an inquiry into the case.
The city's public safety director, Ned Pettus Jnr, appealed for calm while the investigation proceeds and facts are uncovered in what he called "a devastating" loss of life.
"Fast, quick answers cannot come at the cost of accurate answers," Mr Pettus told a late news conference with the police chief and mayor.
"BCI will conduct a fully independent investigation, which will be made public. If an officer has violated policy or the law, if they have, they will be held accountable."
Mayor Andrew Ginther said it appeared from an initial review of the footage that the officer who opened fire "took action to protect another young girl in our community".
"But another young girl will still not be coming home," he said. "I ask everyone to pray for peace ... we pray for this family, we pray for this city, and we pray for our neighbours."
A woman identified in the Columbia Dispatch account as the girl's aunt, Hazel Bryant, told the newspaper that the teenager lived in a foster home and became involved in an altercation with someone at the residence.