PIKETON, Ohio — Eight members of the same family were shot to death in the head Friday at four locations in rural southern Ohio, authorities said. They warned surviving relatives and residents to be careful and said the killer should be considered armed and dangerous.

Three children, ages 4 days to 3 years, survived the grisly killings that left seven adults and a 16-year-old boy dead, said Attorney General Mike DeWine and Pike County Sheriff Charles Reader at an afternoon news conference.

Authorities said preliminary information indicates that none of the eight dead was a victim of suicide. DeWine said it’s possible more than one person was involved in the slayings.

Some of the victims were in bed, indicating they were shot while they were sleeping, authorities said. The victims were identified as members of the Rhoden family.

“It’s heartbreaking,” DeWine said. “The one mom was killed in her bed with the 4-day-old right there.”

A motive isn’t clear, authorities said.

Neighbors and relatives also said the Rhoden family lived in the large area closed off by investigators and its various members of the family lived scattered among three different trailers, including the mother Dana Rhoden, her ex-husband, several children and grandchildren.

“It was a mother, her former husband, their grown children and some grandchildren, too. They all used to attend our church,” said Phil Fulton, pastor of the nearby Union Hill Community Church. Dana Rhoden worked at a nursing home for the elderly, he said. She had just bought a new mobile home near the two existing trailers occupied by her ex-husband and her son, Fulton said. All three trailers are less than a mile apart.

Neighbors and relatives said the ex-husband was one of those killed.

“They were very good people,” said a relative of Dana Rhoden, who did not want to be identified.”She was so good with her kids and her grandbaby. We’re just brokenhearted.”

Many among the Rhoden’s relatives were still awaiting word on exactly which members of the large family were killed, the relative said.

Video from local TV news outlets showed law enforcement vehicles clustered around the trailers on a stretch of Union Hill Road, where authorities say the incident occurred. Neighbors there describe it as a rural area of mostly mobile homes.

Ohio Gov. John Kasich, who was in Pennsylvania for his presidential campaign, said his office was monitoring the situation. “Reports we are receiving from Peebles are tragic beyond comprehension,” wrote Kasich on Twitter, referring to the town bordering Piketon.

Tierney said the Pike County sheriff’s office called state authorities at 8:21 a.m. requesting help. The attorney general sent agents from four of its units: crime scene, special investigations, criminal intelligence and cybercrimes.

Officials at Peebles High School said they placed the school on lockdown Friday morning as a precaution but lifted that lockdown by about 10:30 a.m.

The Washington Post’s Julie Tate contributed to this report.