A gunman has killed 10 people, including a police officer, following an hours-long stand-off at a grocery market in the US state of Colorado.

The attack in Boulder ended with police detaining an injured, shirtless suspect at the King Soopers market.

The shooting was live-streamed by witnesses and broadcast on YouTube.

The incident began at about 14:30 local time (20:30 GMT) on Monday when the suspect entered the supermarket and began firing.

About 20 minutes later, the Boulder police department tweeted that there was an "Active Shooter at the King Soopers on Table Mesa" street.

Police again warned people to avoid the area in a further tweet about two hours later. "Do NOT broadcast on social media any tactical information you might see," the tweet added.

However, some of the stand-off was captured on camera by a passer-by showing victims near the grocery store.

"I don't know what's going on... I heard gunshots, someone's down," the cameraman shouts. "There's an active shooter, get away".

Gunshots can be heard as he runs away from the shop.

The video continues, with police arriving on the scene and surrounding the market.

People said they had to dive for cover or run to safety as the shooting unfolded.

Aerial footage later showed a man, who appeared only to be wearing shorts, being taken away in handcuffs.

Speaking at a press conference, Boulder police chief Maris Herold confirmed that a suspect was in custody and was receiving hospital treatment. "I want to reassure the community that they are safe," she said.

Ms Herold named the officer killed as Eric Talley, a 51-year-old who had been with the Boulder police department since 2010.

BDST: 1228 HRS, MAR 23, 2021
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