HOUSTON (AP) — A sheriff says three people are dead, including two children, in an apparent murder-suicide in the Houston area.

Harris County Sheriff Ed Gonzalez says the children were in the care of their grandmother Thursday when she stepped away for an errand. He says the children were gone when she returned.

The children, a boy and a girl believed to be between 7 and 12 years old, were taken to another residence where they were shot.

The man suspected of taking the children then shot himself. Gonzalez says the man, who hasn’t been identified, is the father of one of the children. His relationship to the second child was not clear.

Gonzalez says it’s “a dark day in Harris County” as authorities contend with another episode of family violence