Seven people including the suspect have died in a shooting at a birthday party in the United States.

The shooter opened fire at the party his girlfriend was attending at Colorado Springs, Colorado, early on Sunday, officials say.

Children at the scene appear to have been spared and have been placed with relatives, a statement released by police and city officials said.

Police found six adults dead inside the mobile home in Colorado Springs.

One other adult male was taken to hospital where he later died of his injuries, police said.

“Words fall short to describe the tragedy that took place this morning,” said Colorado Springs Police Chief Vince Niski.

“As the chief of police, as a husband, as a father, as a grandfather, as a member of this community, my heart breaks for the families who have lose someone they love and for the children who have lost their parents.”

Colorado Springs Mayor John Suthers said, “Today we find ourselves mourning the loss of lives and praying solemnly for those who were injured and those who lost family members in a senseless act of violence on Sunday morning.”

-with AAP/agencies