Six children and two adults have been found handcuffed and fatally shot in the head in a Texas home, following the arrest of a man who exchanged gunfire with police.

The gunfire broke out when officers who had been called to the Houston-area home late on Saturday spotted the body of a child and tried to enter.

A man surrendered about an hour later, after talks with police negotiators.

Police said the suspect, David Conley, was later charged with capital murder.

The Harris County Sheriff's Office said the bodies were found after "a welfare check was conducted on the premises" by deputies at about 21:00 local time (02:00 GMT Sunday).

A man inside opened fire when the deputies tried to force their way in.

The dead were identified as Dewayne Jackson, 50, his wife Valerie Jackson, 40, and children Nathaniel, 13, Dewayne, 10, Honesty, 11, Caleb, nine, Trinity, seven, and Jonah, six.

Nathaniel was believed to be the son of  Conley, 48, and Valerie Jackson from a previous relationship.

Chief Deputy Tim Cannon of the Harris County Sheriff's Office said: "We... cannot fully comprehend the motivation of an individual that would take the lives of so many innocent people. Especially the lives of the youngest.

"The killer's motives appear to be related to a dispute with Valerie."

 Conley is being held in jail without bond.

The officials had previously said the bodies of five children and three adults were found in the house.

Court records showed that  Conley's criminal history dated back to at least 1988, the Associated Press reports.

Last month, he was charged with assault of a family member, the news agency says.