A police officer has been killed and four others have been injured while responding to an early morning domestic dispute in the US state of Colorado.
Authorities confirmed two civilians were also shot by a suspect, who they say is now believed to be dead.
The shooting happened at an apartment complex at Highlands Ranch, south of Denver.
Residents in the area were put on “code red” alert and told to stay inside, away from windows during the incident.
The Douglas County Sherriff’s office advised people to avoid the area and a number of roads were closed while Swat officers responded.
A bomb squad was also pictured at the scene.
An emergency shelter has been set up for anyone evacuated during the investigation.
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The severity of the injuries to the six surviving shooting victims is not immediately known, but local media reported that one hospital which received three of the injured said they were not in a life-threatening condition.
The FBI said they have offered their assistance to local authorities.
Colorado has seen some of the worst mass shootings in US history, including the 1999 Columbine High School shooting in which 13 people, including 12 students, were killed.
It happened just outside of the town of Littleton, which neighbours Highlands Ranch where Sunday’s incident happened.