US police say “multiple people” have been killed in a shooting at a supermarket in Boulder, Colorado, including a police officer.
Boulder police commander Kerry Yamaguchi said a suspect was detained after the incident at the King Soopers store in the Table Mesa area of the city on Monday afternoon.
“We had multiple people who were killed in this incident, and I’m sorry to have to report that one of them was a Boulder police officer,” Mr Yamaguchi told a news conference.
He added that the suspect was believed to be the only individual with injuries who survived the bloodshed.
Boulder County district attorney Michael Dougherty described the incident as a “tragedy and a nightmare”.
A witness told the Associated Press he heard gunshots and saw three people lying face down on the ground, adding that he “couldn’t tell if they were breathing”.
Video posted on YouTube showed one person on the floor inside the store and two more outside on the ground, but the extent of their injuries was not clear.
Another witness, Sarah Moonshadow, 42, told Reuters that shots rang out just as she and her son Nicholas reached the checkout inside the shop.
Ms Moonshadow recounted seeing “someone laying in the road” as she and her son fled the store.
She added: “And I tried to run towards him, and Nicholas pulled me away and he said, ‘We have to go.’ And we just ran and hid behind the building.”
SWAT teams and at least three helicopters were sent to the scene.
Boulder Police did not given further details about the shooting or how many people were killed. They said police were still investigating and didn’t have details on a motive.
Mr Dougherty said authorities know how many people died but suggested they are not releasing more information at this stage because families of the victims have yet to be notified.
The FBI said it is helping with the investigation.
Earlier, Colorado governor Jared Polis tweeted to say he was heartbroken.
He said: “My heart is breaking as we watch this unspeakable event unfold in our Boulder community.”
He called it “very much an active situation” and said the state was “making every public safety resource available to assist the Boulder County Sheriff’s Department”.
White House press secretary Jen Psaki tweeted that President Joe Biden had been briefed on the shooting.
In a statement, the King Soopers chain offered “thoughts, prayers and support” to those effected.