CARNATION, Wash. (AP) — A man and a woman have been arrested in the deaths of six people, likely family members and including two young children, at a rural property east of Seattle, authorities said Wednesday.

The two, a 29-year-old woman and a man in his early 30s, were being held for investigation of homicide, King County sheriff's Sgt. John Urquhart said.

He said it was unclear whether the two are related, but they were known to the victims. The pair came to the crime scene after investigators arrived there this morning, were questioned by investigators, then arrested around 4 p.m.

Urquhart said investigators had not determined a motive in the slayings.

The victims included a boy about age 3, a girl about age 6, a man and woman in their 30s, and a man and woman in their 50s.