Gunfire erupted in a crowded Ohio nightclub early Sunday after a personal dispute boiled over, killing one person and wounding at least 15 as partygoers scattered into the night, authorities said.
The gunmen remained at large following the shooting at the Cameo nightclub in Cincinnati that Police Chief Eliot Isaac said was packed with revelers.
"Several local men got into some type of dispute inside the bar and it escalated into shots being fired from several individuals," Isaac told reporters.
"As a result, there were 16 people that sustained gunshot injuries, one of which is deceased," he said, adding that one victim was in "an extremely critical condition."
Isaac named the man killed at the scene as 27-year-old Obryan Spikes.
Cincinnati Mayor John Cranley said there was "no evidence that this was a terrorist attack."
"However, to the victims, what difference does it make? They've been terrorized by gun violence, innocent victims," he said.
"It's important for everyone to understand that people were just going to have a good time and ended up getting shot. That is totally unacceptable."
Police began receiving calls about shots being fired at the club at about 1:30 am (0530 GMT), according to Isaac.
No arrests have yet been made, and Isaac could not confirm whether any of the injured were among the shooters.
"The investigation is in its very early stages," the police chief said.
Authorities in the Midwestern city called on anyone with information that could help the probe to come forward.
- 'Grown and sexy' -
According to its Facebook page, Cameo admits "grown and sexy" partygoers aged 21 and over on Saturday nights.
"It was a young crowd and we have had incidents in the past, but this is the worst by far," Captain Kimberly Williams, the district's police commander, told CNN.
She said there was "a lot of chaos when the shots went off."
Cameo was the site of two shooting investigations in 2015, local news station WLWT reported.
Someone was shot in the foot there on New Year's Day, and a shooting victim was found in the parking lot in September, WLWT said.
Ohio Governor John Kasich said his office was offering help to local authorities.
"You see things like this and you begin to wonder, where is it safe to go?" he said on CNN.
Although authorities said there was no evidence of terrorism, the attack inevitably raised memories of last year's rampage at a gay nightclub in Orlando, Florida.
That mass shooting -- which left 49 dead and 68 wounded -- was the deadliest terror attack in the United States since September 11, 2001.
The gunman, Omar Mateen, pledged allegiance to the Islamic State jihadist group in a call to police during the assault.
- American gun violence -
But shootings are a common feature of life in America, where the right to bear arms is protected by the US Constitution.
Cincinnati, a city of 300,000 people nestled along the northern banks of the Ohio River, had 66 homicides in 2016, all but nine of them as a result of firearms.
This year has seen a spike in gun violence, with 57 shooting victims in the city as of Thursday last week, compared to 31 during the same period last year.
Elsewhere in the United States, a gunman opened fire Saturday on a double-decker bus on the Las Vegas Strip, killing one person and wounding another. Police said the suspect appeared to have "mental issues."
More notorious gun crimes in recent years included the rampage carried out by 21-year-old white supremacist Dylann Roof, who shot to death nine people during a Bible study session at a historically African American church in Charleston, South Carolina on June 17, 2015.
And a massacre at an elementary school in Newtown, Connecticut on December 14, 2012 claimed the lives of 20 children and six adults. Gunman Adam Lanza, who had a history of mental illness, also killed his mother and went on to commit suicide.
The tragedy sparked calls for stricter gun control laws, but bills banning assault weapons and expanding background checks on gun purchases were defeated in the US Congress.