Police found seven bodies in a US apartment on Sunday after an apparent Christmas Day shooting in which the gunman killed six people before committing suicide, a newspaper reported.

The Dallas Morning News cited police as saying they had found the bodies of four women and three men after responding to an emergency call in the town of Grapevine, near Dallas, Texas.

It cited Grapevine Police Sergeant Robert Eberling as saying that the victims had not yet been identified.

"It's a very tragic situation. It could have been a family gathering, given the time of year," the newspaper quoted him as saying.

"We believe that we have just one shooter that is responsible, and we believe he is among the deceased," Eberling told the paper, without providing further details.

The Grapevine police did not immediately respond to a request for comment.