Editor’s note: This article has been updated to include a response from ICE Denver Public Affairs.

According to local immigration advocacy groups, a federal agency conducted operations in Keystone on Tuesday, Nov. 25.

Voces Unidas President Alex Sanchez said his organization can confirm, based on witness accounts, that an operation took place Tuesday morning near the Village at Wintergreen apartments in Keystone. He said the organization, which advocates for immigrants across the Western Slope, also confirmed local law enforcement was not involved.

Mountain Dreamers Executive Director Peter Bakken said his organization believes U.S. Immigration and Customs Enforcement agents — including at least one from the agency’s Homeland Security Investigations branch, which handles criminal investigations — executed the operation. Mountain Dreamers’ came to that conclusion based on video its staff has viewed from the incident.

Bakken said Mountain Dreamers staff believe, based on eyewitness reports, that agents detained at least one person. Mountain Dreamers posted on Facebook about the incident at about 9:30 a.m. Tuesday. Summit Daily News has not independently verified the detainment.

Lt. Mike Schilling of the Summit County Sheriff’s Office wrote in a text message that the office did not receive a notification from any federal agency about operations in the county Tuesday. ICE has notified the Sheriff’s Office of operations in the county in the past, but it did not notify the office of its operations in September, when the agency detained at least eight people.

Dillon Keystone Police Chief Cale Osborn confirmed to Summit Daily that his department was not involved in the operation and did not receive any prior notice from federal agencies that they would be performing operations in Keystone on Tuesday.

In response to questions about the operation, ICE Denver Public Affairs stated in an email Tuesday that the agency “does not confirm, deny, or otherwise discuss ongoing or future operations” in the interest of “operational security” and safety for its personnel. It stated the agency announces operational results “when appropriate.”

Editor’s note: Summit Daily News reporter Kit Geary contributed to this report.