Bryan E Sweatt kills five people and himself in Greenwood, South Carolina

SIX people have been found dead in a house today.

Greenwood County Sheriff Tony Davis said deputies responded to calls from 27-year-old Bryan E Sweatt, who said he felt "edgy" inside a house in Greenwood, South Carolina, about 6pm Tuesday (7am today AEST).

As police headed towards the property, a neighbour called emergency services and said two children from the home arrived at his doorstep saying someone had fired shots.

Armed officers waited outside the property as negotiators attempted to make contact with Sweatt, who if from Greenwood, and the other people inside.

After no one responded for more than two hours, the county's SWAT team made entry into the house and found the victims and their suspected killer shot dead. There are reports that several people inside the home were bound with duct tape.

The deputies classified the massmurder as a "boyfriend/girlfriend ... domestic situation".

"I think South Carolina, I saw on the inteet, is number five in the nation as far as violence. We rank pretty high as far as domestic violence. I wish I had an answer for it. I don't" said Davis outside of the home.

Four adults, including Sweatt and a couple, and two children, believed to be nephews, were found.

Davis confirmed in a press conference at the location of the crime scene that the age of the deceased ranged from 9- to early 50s, 7WPSA reported.