SACRAMENTO, Calif >> The usual crowds filled the streets as bars and nightclubs were closing in California’s capital city of Sacramento when the sound of rapid-fire gunshots sent people running in terror. In a matter of seconds, the latest U.S. mass shooting had left six people dead and 12 wounded.

Sacramento police said they were searching for at least two people who opened fire around 2 a.m. Sunday on the outskirts of the city’s downtown entertainment district, anchored by the Golden One Arena that hosts concerts and the NBA’s Sacramento Kings.

The team’s home game against the Golden State Warriors went on as scheduled Sunday night and began with a moment of silence for the victims.

Police Chief Kathy Lester revealed few details from the investigation and pleaded with the public to share videos and other evidence that could lead to the killers.

“The scale of violence that just happened in our city is unprecedented during my 27 years here,” Lester told reporters during a news conference at police headquarters. “We are shocked and heartbroken by this tragedy. But we are also resolved as an agency to find those responsible and to secure justice for the victims and the families.”

Sacramento Mayor Darrell Steinberg and other city officials decried escalating violence in the city while also urging people to keep coming downtown for events like NBA games and performances of the Broadway musical “Wicked.”

“We can never accept it as normal and we never will,” Steinberg said of the shooting. “But we also have to live our lives.”

The gunfire erupted just after a fight broke out on a street lined with an upscale hotel, nightclubs and bars, but police said they did not know if the altercation was connected to the shooting. Video from witnesses posted on social media showed rapid gunfire for at least 45 seconds as people screamed and ran for cover.

The gunfire startled sleeping guests at the Citizen Hotel, which included a wedding party and fans of the rapper Tyler the Creator, who performed at a concert hours earlier.

From her window on the fourth floor of the hotel, 18-year-old Kelsey Schar said she saw a man running while firing a gun. She could see flashes from the weapon in the darkness as people ran for cover.

Schar’s friend, Madalyn Woodward, said she saw a girl who appeared to have been shot in the arm lying on the ground. Security guards from a nearby nightclub rushed to help the girl with what looked like napkins to try to stanch the bleeding.

Police found a stolen handgun, but they did not know if it had been used in the shooting. The dead included three men and three women. Authorities were still working to notify family members, and had publicly identified only one victim as of late Sunday, 38-year-old Sergio Harris, without providing a cause of death. Of the 12 wounded, at least four had critical injuries, according to the Sacramento Fire Department.

Sunday’s violence was the third time in the U.S. this year that at least six people have been killed in a mass shooting, according to a database compiled by The Associated Press, USA Today and Northeastern University. And it was the second mass shooting in Sacramento in the last five weeks.

President Joe Biden called for action on gun crimes in a statement Sunday.

“Today, America once again mourns for another community devastated by gun violence,” Biden said. “But we must do more than mourn; we must act.”

On Feb. 28, a father killed his three daughters, a chaperone and himself in a Sacramento church during a weekly supervised visitation. David Mora, 39, was armed with a homemade semiautomatic rifle-style weapon, even though he was under a restraining order that prohibited him from possessing a firearm.

The crime scene Sunday sprawled across two city blocks, closing off a large swath of the city’s downtown. Bodies remained on the pavement throughout the day as Lester said investigators were working to process a “really complex and complicated scene” to make sure investigators gathered all the evidence they could to “see the perpetrators of this crime brought to justice.”

Councilmember Katie Valenzuela, who represents the area, said she’s fielded too many phone calls reporting violence in her district during her 15 months in office. She cried at a news conference as she told reporters that the latest phone call woke her up at 2:30 a.m. Sunday.

“I’m heartbroken and I’m outraged,” she said. “Our community deserves better than this.”