At least 14 people have been shot outside a funeral home in Chicago - one of the worst mass shootings in a city already grappling with rising violence.
Mourners were shot at by the occupants of a passing vehicle as they left the home in Gresham, on Chicago's South Side, on Tuesday evening, police said.
The injuries were reported to range from serious to critical.
The shooting comes amid reports that federal agents are to be deployed to the city to help tackle rising crime.
Mayor Lori Lightfoot said she had been assured that the agents would work "collaboratively" with Chicago's police force, local media report. She had previously threatened to sue US President Donald Trump if he sent in troops without her permission.
The president has sent federal agents to Portland, Oregon, and threatened to do the same with other major US cities, blaming their Democrat leaders for allowing protests over the death of George Floyd to descend into violence.
Responding to the shooting at the funeral home in a series of tweets, Ms Lightfoot urged anyone with information relating to the incident to "please come forward or submit a tip anonymously".
Police say they believe the shooting was gang-related.
The shooting in Gresham happened at around 18:30 local time (23:30 GMT) as mourners left the funeral of a man who had been fatally shot in another part of the city last week. A police squad car had reportedly been assigned to guard the event.
Police said a black vehicle sped past the funeral home opening fire on those leaving. Some mourners exchanged gun fire. The car crashed in an adjoining street and its occupants fled the scene, although one person has been taken into custody and is being questioned by police.
One witness to the attack told the Chicago Sun-Times: "We went out in the street and all we saw was bodies just laying everywhere. They were shot up everywhere."
Chicago Police First Deputy Supt Eric Carter said 60 bullet casings were found at the scene.
He said all the victims were adults and were being treated at five different hospitals in the area.
On Wednesday, Supt David Brown described the shooting as part of "the cycle of violence in Chicago".
"Someone gets shot, which prompts someone else to pick up a gun. This same cycle repeats itself over and over and over again. This cycle is fuelled by street gangs, guns and drugs."
Local media say this is one of the worst mass shootings in Chicago's recent history.
Gun crime in Chicago has surged in recent weeks. The city saw its deadliest day in at least 30 years on 31 May when 18 people were killed in a 24-hour period. The city's 911 emergency call centre received 50,000 more calls than on an average day, Ms Lightfoot said.
The death of George Floyd, a black man, at the hands of a white police officer in Minneapolis on 25 May sparked a wave of largely peaceful protests in US cities demanding police reform and racial equality.
Some cities, however, have also seen an increase in violence, arson, damage to property, arrests and allegations of police brutality.
After sending federal officers to quell the violence in Portland, Mr Trump has threatened to do the same in other cities run by "liberal Democrats" who he said were afraid to act. He included Chicago and New York.
On Tuesday, Ms Lightfoot said she had been assured by the Trump administration that there would be no "Portland-style deployment", but that she would remain vigilant for any abuse of power if federal assistance is given to the city.