Updated

Three mentally disabled brothers were found dead in a house fire that appears to have been fueled by a flammable liquid in several spots.

The deaths are being treated as homicides because of the discovery of the flammable liquid. Police haven't ruled out that one or more of the brothers may have started the blaze Thursday in Shenango Township, and stressed that there's no immediate threat to the public.

Richard Fombelle, 57; Robert Fombelle, 56; and Daniel Fombelle, 50, had lived alone in the home since their mother died. Nearly everyone else who lives on the secluded, dead-end road is related, including the men's aunt, who lives next door. Family members contacted Friday declined comment.

"The aunt next door could smell smoke around 5 o'clock this morning," state police Cpl. Jeffrey Martin said Thursday. "They investigated in her house and couldn't find anything. It wasn't until 7:30 (a.m.) when someone passing the house actually saw the fire."

A relative who called 911 said the brothers were mentally disabled, but police and family members haven't specified their disabilities.

Township fire officials initially said they found nobody inside the house, even after searching the basement. The bodies were found hours later, close to one another in a portion of the basement not immediately accessible, police said.

Autopsies were expected Friday, though investigators suspect the men died from smoke inhalation, Lt. Eric Helmick said.

Police couldn't immediately be reached for comment Friday, but they told reporters at the scene that the case is suspicious and being treated as a homicide case pending further tests on the evidence and more investigation.

A dog trained to assist in arson investigations determined the fuel used to start the fire also was found inside a vehicle outside the home that burned. Some fuel was spilled outside the residence, and in at least two other spots in the home where the fire began, police said.

"Right now, we are going to start it at the worst-case scenario and rule it as a homicide for now, and work backwards from there," Helmick said.