PIKETON, Ohio — Authorities urged residents to be cautious in this part of rural southern Ohio heading into the weekend as the search continued for whoever fatally shot eight members of a family at four different properties.

Investigators interviewed more than 30 people hoping to find leads in the deaths of the seven adults and 16-year-old boy whose bodies were found in homes southwest of Piketon on Friday.

All victims were shot in the head, police said, and it appeared some were killed as they slept, including a mother in bed with her 4-day-old nearby. The infant and two other small children were not hurt.

Authorities didn’t release the victims’ names but said they’re members of the Rhoden family. Investigators said none of the deaths appeared self-inflicted, so they believe at least one assailant is at large.

Law enforcement officials say whoever is responsible for the killings should be considered armed and dangerous.

A motive for the slayings isn’t known, authorities said, but they urged surviving members of the Rhoden family to take precautions. Pike County Sheriff Charles Reader also recommended area residents be extra wary.

“This really is a question of public safety, and particularly for any of the Rhoden family,” Attorney General Mike DeWine said.