The shooting incident prompted a heavy police presence in the area, with the department reiterating warnings to keep away, stressing that the situation is still "very active".
According to media reports, at least six people, including a police officer, have been shot and killed. No official confirmation from police has followed.
Shortly after the King Soopers alert was announced, Boulder police urged people in another location, "near 17th and Grove", to shelter in place. At the time, the authorities were investigating whether the incident in the second location was connected to the King Soopers shooting.
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