The Boulder Police Department said it was responding to an "attack" in Colorado on Sunday afternoon, according to a post from the department on X, formerly Twitter.
"We are responding to a report of an attack at 13th and Pearl streets with reports of several victims. PLEASE AVOID THE AREA! We will put out more information soon," the department's post reads.
In a follow up post, the Boulder Police Department wrote that it evacuated the areas around 1200, 1300 and 1400 blocks of Pearl Street between Walnut and Pine, with some expansions.
Newsweek has reached out via phone and email Sunday during non-working hours to the Boulder Police Department, the Boulder Fire Department, FBI Denver, Colorado Governor Jared Polis, as well as the Colorado Bureau of Investigations and Local ATF for more information.
The area, known as Pearl Street Mall, attracts visitors and locals with its shops and restaurants. It is also the site of many local performances and demonstrations.
Boulder sits about 30 miles north of Denver, tucked into foothills of the Rocky Mountains on the regions front range.
On Sunday afternoon, Boulder police said they were responding to what they called an "attack." They did not say what the nature of the attack was.
It's also unclear what kind of injuries the victims sustained, what the ages of those victims are, or if there are suspects apprehended.
The official event calendar for the Pearl Street Mall listed a book discussion at Ozo Coffee, a concert at the First United Methodist, and an event called Sundays on West Pearl, which features mini art workshops.
This is an ongoing investigation and local law enforcement said they will release more information soon.
This is a breaking news story and will be updated as more information becomes available.