One police officer discharged their firearm during the rescue, according to police, however no one was hit.
Boulder Police Department said in a tweet: “During the rescue, one officer fired their gun. No one was struck. Though the victims were rescued, the suspect then barricaded himself inside the home.
“He is believed to be armed with multiple firearms. Officers are evacuating people nearby and working to take him safely into custody.”
Police have since confirmed that the suspect had been taken into custody but urged people to continue to avoid the area near the intersection of Iris Avenue and Broadway.
Previously, there were also reports of a boobytrapped window and even a dog at the scene.
Residents were reportedly being evacuated from the area as officers worked to bring the suspect into custody.
A local news outlet had previously reported people killed at the scene, however Boulder Police have stated their were “no confirmed reports of any fatalities”.
The outlet also reported that, according to traffic on police scanners, the suspect may have had two AK-47 rifles along with a dog strapped with explosives.
Boulder Police did not confirm the report but have said they will provide updates as the situation develops.
The department said at 12.47am MST (7.47am GMT): “UPDATE: Suspect in custody. Please continue to avoid the area while we process the scene. We will tweet when the intersection is back open.”
More to follow.