(CNN) - Five sheriff's deputies were shot and one of them killed following a domestic disturbance call in a Denver suburb, according to the Douglas County Sheriff's Office.
Two civilians also were shot and the suspect is "shot and believed to be dead," the sheriff's office said on Twitter.
Residents in the area were ordered to shelter in place.
There was no immediate information on the condition of the injured deputies or civilians, the sheriff's office tweeted, saying "the scene remains active."
The FBI office in Denver said it is aware of the incident and has offered its full support to the sheriff's office.
"Any citizens in the affected area are instructed to shelter in place, avoid windows and stay away from exterior walls," the office tweeted. An emergency shelter has also been set up for those displaced by the massive police response.