A gunman has shot dead four people and wounded up to four more in two separate but related shootings in Texas in the US.

The first attack came around 10.30pm local time on Wednesday night at a house on Long Canyon Trail in southwest Dallas. Two people died and two more were wounded, according to police sources.

The man was apparently looking for his ex-girlfriend, but she was not at the home. The suspect is then said to have driven seven miles to another house in the suburb of DeSoto. A further two people were killed and one or two others were injured.

Some of the victims are thought to be children. Some of the wounded were said to be in a critical condition.

The authorities say a man, who initially claimed to be a victim, was arrested.

Dallas police told WFAA-TV that the suspect only stopped shooting when he ran out of ammunition. The TV station said the man has tattoos identifying him as a former member of the military.

Officials gave no details about what led to the shooting spree, but initial indications point to a domestic dispute.